1. What is a Mobile Device?
Ans: A mobile device is a handheld tablet or
other device that is made for portability, and is therefore both compact and
lightweight.
These devices are designed to be extremely
portable, and they can often fit in your hand. Some mobile devices like tablets, e-readers, and smartphones are powerful
enough to do many of the same things you can do with a desktop or laptop
computer.
In the computer world, the term mobile device refers to any electronic device that be easily moved from one location to another. Over time, this category has expanded to include cell phones, laptops, smartphones, smartwatches, and other portable devices.
2. What is a Mobile OS?
Ans: A mobile operating system (mobile OS) is an operating system
built exclusively for a mobile device such as a smartphone, personal digital
assistant (PDA), tablets, smart watches or other
mobile devices.
A mobile operating system (OS) is software that allows
smartphones, tablet PCs (personal computers) and other devices to run
applications and programs. A mobile operating system is an
operating system that runs only on mobile devices. It is similar kind of
software as the computer operating systems like Linux, Windows and Mac, but is
relatively simple and light.
3. Name Four Mobile OS.
Ans: The name of four mobile OSs are Android, iOS, Windows phone OS, and Symbian.
4. What is GSM technology? Or Define GSM?
Ans: GSM stands for Global System for Mobile Communications. It is a
standard that specifies how 2G (second generation) cellular networks operate.
GSM was a significant improvement over the first generation of cellular
networks and represented a transition from analog to digital
telecommunications.
It is a widely used mobile communication
system in the world. GSM is an open, digital cellular technology used for
transmitting mobile voice and data services.
GSM technology was developed as a digital
system using the time division multiple access (TDMA) technique for
communication purposes. GSM was developed using digital
technology. It has the ability to carry 64 kbps
to 120 Mbps of data rates.
5. What is LTE?
Ans: LTE stands for “Long Term Evolution” and it is most commonly used in connection with 4G, the fourth-generation global wireless communication standard that was first defined in 2008. It is a standard for high-speed cellular data communication systems. It provides a download speed of about 100 Mbps and an upload speed of about 50 Mbps. It does not provide good quality voice calls while using the data services. This problem can be easily solved by VoLTE connectivity. In India, Airtel launched its first LTE service in 2012.
LTE (Long-Term Evolution) is a fourth-generation (4G) wireless standard that provides increased network capacity and speed for cellphones and other cellular devices compared with third-generation (3G) technology.
6. Differentiate LTE from VoLTE.
Ans:
LTE | VoLTE |
LTE stands for Long Term Evolution. | VoLTE stands for Voice Over Long Term Evolution. |
A standard for high speed wireless communication for mobile devices and data terminals. | A standard for high speed wireless communication for mobile devices and data terminals including IoT devices and wearables. |
It may or may not support voice call and data services at the same time. | It supports data and call services at a similar time. |
Reduce the voice quality when using voice and data at the same time. | You can enjoy good voice calling when using the data services. |
The data will get off when the voice call is happening. | At the time of the voice call, it does not turn off the data. |
The call connection speed is slow | The call connection speed is high. |
The users need to have external softwares to make video calls on LTE networks such as whatsapp, facebook messanger, skype etc. | The users need not have an external softwares to make video calls but just phone phone number is required to video call anybody. |
It is not widely used by users nowadays. | It is used by most people nowadays. |
7. What is a cell phone sensor?
Ans: The sensor in a phone refers to the components of the phone that can be felt by the chip, such as distance, light, temperature, brightness, and pressure. These sensors are getting smaller and smaller, their performance is increasing stronger, and their cost is getting lower and lower, just like all electronic components.
The mobile phone's program software analyzes and calculates the various data acquired by the sensors to develop numerous apps. Today's mobile phones have made social networking, financial transactions, sports tracking, entertainment, and learning extremely convenient.
Ans:
- Android OS: Developed by Google Inc.
- iOS: Developed by Apple Inc.
- Windows Phone OS: Developed by Microsoft
- BlackBerry OS: Developed by BlackBerry Limited
9. What is WAP?
Ans: WAP stands
for Wireless Application Protocol. Wireless application protocol (WAP)
is a communications protocol that is used for wireless data access through most
mobile wireless networks. WAP enhances wireless specification interoperability
and facilitates instant connectivity between interactive wireless devices (such
as mobile phones) and the Internet.
It
facilitates easy connectivity between mobile and the Internet and enhances
wireless inter-operability.
WAP helps
in accessing wireless data through all the communication networks. It is a
communication protocol and helps maintain the connection of mobile devices in
the network and the internet. Information can be accessed easily, and a web
browser is provided for devices that use the WAP network. Only if the devices
are connected with Wi-Fi, WAP provides information about the devices.
Connectivity is provided faster in the devices, and they follow the protocol of
WAP. Internet services are provided in the devices with the help of WAP. WAP
also helps to cover the network at larger distances.
10. Define
GPRS?
Or
What is meant by GPRS?
Ans: GPRS (General Packet Radio Service) is a very widely-deployed wireless data service, available now with most GSM networks. It is a packet oriented mobile data service on the 2G on GSM.
GPRS offers throughput rates of up to 40 kbps, enabling mobile handsets to access online services at a similar speed to a dial-up modem, but with the convenience of being able to connect from almost anywhere.
GPRS enables people to enjoy advanced, feature-rich data services, such as e-mail on the move, multimedia messages, social networking and location-based services.
11. What are subsystems in GSM system?
Ans:
- Radio subsystem (RSS)
- Network & Switching subsystem (NSS)
- Operation subsystem (OSS)
12. Explain
GSM, GPRS?
Ans:
GSM: GSM stands for Global System for Mobile
Communications. It is a
standard that specifies how 2G (second generation) cellular networks operate.
GSM was a significant improvement over the first generation of cellular
networks and represented a transition from analog to digital
telecommunications.
GSM is the most widely accepted standard in telecommunications and it is implemented globally. It is an open, digital cellular technology used for transmitting mobile voice and data services. GSM was developed using digital technology. It has an ability to carry 64 kbps to 120 Mbps of data rates.
GSM technology
was developed as a digital system using the time division multiple access
(TDMA) technique for communication purposes. Presently GSM supports more than
one billion mobile subscribers in more than 210 countries throughout the world.
GSM provides basic to advanced voice and data services including roaming
service. Roaming is the ability to use your GSM phone number in another GSM
network.
GPRS:
GPRS (General Packet Radio Service) is a very
widely-deployed wireless data service, available now with most GSM networks. It
offers throughput rates of up to 40 kbps, enabling mobile handsets to access
online services at a similar speed to a dial-up modem, but with the convenience
of being able to connect from almost anywhere.
GPRS provides computer and mobile users with a
steady Internet connection. The packet-oriented characteristic enhances the
data transfer speed. In order to make use of GPRS, users should possess a
terminal or mobile phone that has GPRS support, and a GPRS-compatible mobile
network subscription.
Advantages
of GPRS:
High-speed:
GPRS offers an optimum speed of 171.2 kbps, which is almost three times quicker
than the data transfer speed of fixed telecommunications networks. Also, it is
ten times faster than the existing GSM network services.
Instant
connection and immediate data transfer: GPRS provides
instantaneous and steady connections, which permit data to be sent wherever and
whenever required.
Cost-effective
solution: Minimizes the incremental expenditure required for
providing
data services. This in turn enables increase in the penetration of data
services amongst business and consumer users
Innovative
and superior applications: GPRS facilitates usage of Internet
applications
over mobile networks. This includes Web browsing, IM messages, e-commerce and
location oriented applications. In addition, it allows for file transfer and
the ability to remotely gain access for monitoring or controlling machines and
house appliances.
13. What
is the frequency range of uplink and downlink in GSM network?
Ans:
The frequency range of uplink in GSM network is
890-960 MHz
The frequency range of downlink in GSM network is
935-960 MHz
14. Mention
the advantages and disadvantages of GSM.
Ans:
Advantages and disadvantages of GSM:
GSM is a cellular technology used for transmitting mobile voice and data services developed by European Telecommunications standards Institutes to describe the protocols for second generation digital cellular networks.
GSM provides standard features like cell phone encryption, data networking,
caller ID, call forwarding, call waiting, SMS and conferencing and it can be
used in an application like home automation, mobile technology, toll
collection, energy conversion etc. GSM has both advantages and disadvantages of
which consumers should be aware of.
Advantages of GSM:
- More suitable network with robust features.
- No roaming charges on International calls.
- Worldwide connectivity and extensive coverage.
- The phone works based on the SIM card so that it is easy to change the different varieties of phones by users.
- GSM signals don't have any deterioration.
- Easy to integrate GSM with other wireless technology such as CDMA and LTE.
- It has the ability to use repeaters.
- Because of the pulse nature of transmission talk time is generally high.
Disadvantages of GSM:
- It can interfere with certain electronics, such as hearing aids that are due to pulse transmission technology. As a result, many locations, such as hospitals, airports and petrol pumps require cell phones to be turned off.
- To increase coverage repeaters are required to be installed.
- It provided limited data rate capability so for high data rate advanced version of GSM devices are used.
- GSM has fixed maximum call sites range up to 35 km that is very limited.
- There is no end-to-end encryption of user data.
- Several incompatibilities within the GSM standards.
- Electromagnetic radiation is more with the use of GSM.
15. What
does SIM card contain?
Ans:
- a personal identity number(PIN)
- a PIN unblocking key(PUK)
- an authentication key
- the international mobile subscriber identity(IMSI)
16. What is CDMA
Ans: CDMA stands for ‘Code Division Multiple Access’. CDMA is a digital cellular network standard that utilizes spread-spectrum technology. It is the standard access method that follows mobile phone applications.CDMA is a channel access method
used primarily by mobile communication technologies. It allows multiple access
which means several transmitters can send information simultaneously over a
single communication channel. Different CDMA codes are assigned to different
users and for the entire duration user can access complete bandwidth. There is
no limit on user frequency range and user uses available bandwidth completely.
There is no undue interference and users can share a band of frequencies. CDMA
technology is used in military, commercial applications, mobile communications,
Radar, and navigation systems.
In CDMA, multiple users are allotted different codes that consist of sequences of 0 and 1 to access the same channels. A special coding scheme is used that allows signals from multiple users to be multiplexed over the same physical channel.
17. What is
UMTS?
Ans: The Universal Mobile Telecommunication System (UMTS) is a third generation (3G) mobile communications system that provides a range of broadband services to the world of wireless and mobile communications.
18. What do
you mean by MMS?
Ans: The multimedia messaging service (MMS) transfers asynchronous multimedia content. MMS supports different media types such as JPEG, GIF, text and AMR coded audio. There is no fixed upper bound for the message size. Depending on the network operator and device capabilities typical sizes are 30100 Kbytes.
19. What is
iOS?
Ans: iOS is a closed and proprietary operating system fully owned and controlled by Apple and not designed to be used by various mobile phone vendors on their systems.
On 9 January 2007,
Apple declared that it would launch iPhone using iOS as the operating system.
The first iOS, called iOS 1, was released on 29 June 2007.
20. Explain
feature of 2G and 3G.
Ans:
2G
- Data speeds of up to 64 kbps
- Use of digital signals instead of analog
- Enabled services such as SMS and MMS (Multimedia Message)
- Provided better quality voice calls
- It used a bandwidth of 30 to 200 KHz
- Speed of up to 2 Mbps
- Increased bandwidth and data transfer rates
- Send/receive large email messages
- Large capacities and broadband capabilities
21. Write a short note on WIFI and WIMAX.
Ans:
WiFi: WiFi stands for Wireless Fidelity. WiFi uses Radio waves to provide wireless high-speed internet and network connections. A WiFi connection is established using a wireless adapter to create hotspots. WiFi antennas size small enough to ne placed on a very small router. WiFi can be used to connect with printer, computers, gaming consoles and many more.
WiMax:
WiMax stands for Wireless Inter-operability for Microwave
Access. WiMax uses licensed or unlicensed spectrum to deliver connection to
network. WiMax handle a larger inter-operable network. WiMax can be used to
provide internet services such as mobile data and WiFi spots.
23. How is GPRS higher than 2G?
Ans:
General Packet Radio Service (GPRS) is an extension of GSM and is considered to be the 2.5
generation technology. It is based on packet switching compared to circuit
switching used in 2G. This was a significant improvement over 2G and helped to
reduce call costs dramatically. It allows users to remain connected to the
Internet without incurring additional charge and supports multimedia
capabilities including graphics and video communications.
24. How is 3G higher than GPRS?
Ans: The 3G systems support much higher data transmission
rates and offer increased bandwidth, which makes them suitable for high-speed
data applications as well as for high quality traditional voice calls. The 3G
systems can be considered to be purely data networks, since voice signals are
converted to digital data.
25. What are the different 1G standards used?
Ans:
AMPS
(Advanced Mobile Phone System) in the USA
NMT 450 (Nordic Mobile Telephone) in
various European countries
TACS
(Total Access Communications System) in the UK
26. List
out the limitations of GPRS.
Ans: Speeds of 177.2 kbps would require a user to use all eight timeslots without any error protection - which simply won't happen. Initial terminals are likely to use only 1-3 timeslots anyway, limiting the available bandwidth to a GPRS user.
When GPRS packets are sent to a destination they are sent in all different directions - allowing for the potential for one or some of those packets to be corrupted or even lost altogether during the data transmission over the radio link. This is inherent in wireless packet technologies so data integrity and retransmission strategies are incorporated - which in turn result in potential transit delays.
Although available radio resource can be concurrently shared between several users, an increase in the numbers of users will slow data services down for each user.
27. List out the
features of android.
Ans:
Features
of Android:
Beautiful UI: Android OS basic screen provides a beautiful and intuitive user interface.
Storage: SQLite, a
lightweight relational database, is used for data storage purposes.
Connectivity: Supports GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, WiFi, LTE, NFC and WiMAX.
Messaging: Supports both SMS and MMS.
Web browser: Based on the open-source WebKit layout engine, together with Chrome’s V8 JavaScript engine supporting HTML5 and CSS3.
Media support: Support the following media: H.263, H.264 (in 3GP or MP4 container), MPEG-4 SP, AMR, AMR-WB (in 3GP container), AAC, HE-AAC (in MP4 or 3GP container), MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, and BMP
Hardware: support
Accelerometer Sensor, Camera, Digital Compass, Proximity Sensor, and GPS.
Multi-touch: Android has
native support for multi-touch which was initially made available in handsets
such as the HTC Hero.
Multi-tasking: User can jump from one task to another and same time various applications can run simultaneously.
Flash support: Android 2.3 supports Flash 10.1.
Tethering: Supports sharing of Internet connections as a wired/wireless hotspot
Wi-Fi Direct: A technology that lets apps discover and pair directly, over a high-bandwidth peer-to-peer connection.
28. List out the GPRS applications.
Ans:
Chat: It is used as means to communicate and discuss matters of common interest. GPRS will offer ubiquitous chat by integrating Internet Chat and Wireless Chat using SMS and WAP.
Multimedia Services: Multimedia objects like photographs, pictures postcards, greeting cards and presentations, static web pages can be sent and received over the mobile network. It can be used for monitoring parking lots or building sites for intruders and thieves. This can also be used by law enforcement agents, journalists and insurance agents for sending images of accident site.
Virtual Private Network: GPRS is used to provide VPN services. As the bandwidth is higher so many banks in India are migrating to GPRS-based networks. This is expected to reduce the transaction time by about 25%.
Vehicle Positioning: This application integrates GPS that tell people where they are. Anyone with a GPS receiver can receive their satellite position and thereby find out where they are. Vehicle positioning applications can be used to deliver several services including remote vehicle diagnostics.
29. Write the features of 3G data service.
Ans: The ITU (International Telecommunication Union)
has proposed 3G telecommunications standards to provide cost efficient high
quality, wireless multimedia applications and enhanced wireless communications.
The features of 3G can be divided into two categories. One is data rates and
the other is security.
The main feature of 3G technology is
that it supports greater voice and data capacity and high data transmission at
low-cost. 3G mobiles can operate on 2G and 3G technologies.
The second major feature is the
security: 3G offers greater security features than 2G like Network Access
Security, Network Domain Security, User Domain Security and Application
Security.
This technology provides localized
services for accessing traffic and weather updates. Video calls and video
conference is another major feature in 3G mobile technology. These features
reduce the communication barriers between people that were not sacked even with
mobile phones.
Data transfer rates are high and can
support even live TV channels over phone. Online media is another exciting
feature in 3G mobiles. 3G mobiles highly attract the music lovers as they can
listen to music and watch videos online and can download huge files with in
less time.
30. Give the difference between the network 1G, 2G, 3G, 4G, 5G mobile communications?
Ans:
1G: only voice communication
G stands
for generation here. The first generation 1G came around 1980.
In this network system, users can do voice calls only. It was using only analog
signal.
2G: Communicate
voice as well as data signals
The
second generation of mobile network system was developed in 1991. This
network system was using the digital signal for data transmission. The more
features were added in 2G as more people can communicate simultaneously and
improved the security with signal encryption. In this technology SMS and MMS
were introduced. GSM and CDMA standards
were introduced by 2G.
3G: Mobile devices communicate at even higher data
rates and support voice, data , and multimedia streams. High data rates in 3G
devices enable transfer of video clips and faster multimedia communication.
The 3G was developed
during the late 90s, but it was introduced around 2001. It provided both voice
and data services. It has more data capacity and good voice quality in calls.
More calls can be done using same frequency range with faster data transfer
speed.
4G: 4G has changed the entire world and smart phones came
into the picture. In India, Reliance Jio has launched the 4G first with free of
cost and rapidly changed the market of smart phones and internet. 4G provides
better speed and given the access to wireless devices with interactive
multimedia, voice, radio, internet and broadband service.
5G: It currently in the under-construction stage. It will be faster and cost effective than other
four generations. It will be more helpful
for IoT and Machine to Machine (M2M) communication. M2M means a direct
connection between wired and wireless devices. It allows transferring data in
Gbps. It is expected that it will support all the devices of the future
with IoT.
31. Briefly explain Mobile Technology?
Ans: Mobile technology is a type of
technology in which a user utilizes a mobile phone to perform
communications-related tasks, such as communicating with friends, relatives,
and others. It is used to send data from one system to another.
Mobile technology is largely employed in
cellular communication systems and other related areas. It employs a network
architecture that allows multiple transmitters to deliver data on a single
channel at the same time. Because it reduces the potential of frequency
interference from two or more sources, this platform allows multiple users to
use single frequencies. The channel has evolved over time.
32. What is APK builder?
Ans:
APK builder is a free platform for
you to make your apk file with zero programming knowledge. To generate your APK
file you have to select
your business’s niche, choose
templates, insert the URL (if needed), and follow other simple steps.
33. Explain the use of
Google Play Store.
Ans: You can install apps, games, and digital content on
your device from the Google Play Store. Google Play
Store is the official distribution storefront for Android applications and
other digital media, such a music, movies and books, from Google. It is
available on mobile devices and tablets that run the Android
operating system (OS).
Google Play
Store is a great resource for apps, games, books, and movies that you can use
on your phone. It gives you a
wide selection of apps you can download on to your Android devices. If you're
just looking for some great entertainment, you can also find music, ebooks, and
movies on the Play store. It really is a one-stop shop.
34. What is Android?
Ans:
Android is an
operating system used on mobiles, smart TVs, tablets, and many other devices.
Android is provided by Google and is continually updated, improved, and
extended. This makes the development of apps for Android smartphones and
tablets both exciting and challenging.
Android is an open-source mobile OS developed by Google and launched in 2008. Android is a Linux-based OS that uses Linux 2.6 to provide core services such as security, memory management, process management, network stack, and a driver model. It offers a wide range of libraries that enable the app developers to build different applications. Android applications are usually written in Java programming language.
35. What is WCDMA?
Ans: WCDMA is a mobile communication
system of the 3rd generation that uses CDMA technology over a frequency
band that is wide enough to provide efficient voice and high-speed multimedia
services. Its infrastructure is compatible with the system of mobile radio
complication of GSM.
Upgrading or installing WCDMA technology-led
mobile service providers to give their services of customers wireless broadband and
more efficiently upgrade their system. This system is composed of radio towers,
packet data interconnection systems, and mobile devices.
36. What is UMTS?
Ans:
The UMTS mobile cellular system of the third
generation for networks is generally based on the GSM standard. Maintained and
uploaded by the 3GPP, UMTS is one of the components of the standard set as International
Telecommunication Union IMT-2000 and compares with the standard set as CDMA
2000.
UMTS uses W-CDMA technology of
radio access to offer spectral bandwidth and efficiency to mobile network
operators. it specifies a system of the complete network which consists of the
core network, user’s authentication via SIM cards, and the radio access
network. The technology mentioned in
UMTS is also known as 3GSM or FOMA (Freedom of Mobile Multimedia Access).
37. Compare WCDMA with GSM
Ans:
WCDMA
(Wideband Code Division Multiplexing Access) and GSM are two technologies that
are used in mobile telecommunications. The difference between these two is that GSM is a 2G technology and WCDMA is a part of the
newer 3G group of technologies. Being newer and more advanced, WCDMA is now the
technology that people want and it is slowly being deployed in a lot of areas
that are already being occupied by GSM. Sooner or later, the WCDMA network would equal the
coverage of GSM, making the GSM network redundant. With this said it is clear that
the GSM network is slowly being phased out and replaced with the newer and
better WCDMA. But for now, GSM is still the most widespread technology that is
used in the whole world.
Let us discuss some of the major key differences between WCDMA and GSM:
- Though both are developed for mobile communications, GSM is used in 2G networks and WCDMA is used in 3G networks. Most people prefer WCDMA to be used as it is newer and transfers 3G data that is faster than 2G data. It is covering the area of GSM and GSM is not being used much nowadays.
- The phones are developed based on the network. Some phones are developed to support only GSM networks whereas some support only WCDMA. Hence, it becomes difficult for these phones to support any other networks in their devices. Nowadays, newer phones are developed to support both the networks so that it is easy to switch from one network to another. Compatibility is offered in phones nowadays so that phones can switch between one network to another. While selecting a mobile phone, it is important to check the specifications to know whether it is compatible with any networks.
- After the 3G is developed GSM is in an improvised version and the advantages are more while we use GSM. Though it was developed to support 2G, 3G settings help GSM to improve itself. Code division is not used in GSM as there would not be many complications in the system. While in WCDMA, code divisions are used to divide the channels so that proper understanding of all the channels and the networks are made by the user. WCDMA is also used along with GSM so that 2G and 3G supports can be made in the phones.
- GSM has the frequency bands of 900, 1800, 1900, and 2100 MHz but the data transfer is not faster and compatible when compared with WCDMA
- As GSM is a list of protocols in the networking system, freedom in the network is not offered as much as WCDMA. In WCDMA, a complete network system is offered without depending on any other networks so that efficiency and bandwidth are more than GSM in the network.
38. List the functions of OS.
Ans:
Functions of OS are as follows:
- Memory Management
- Process Management/CPU Scheduling
- Device Management
- File Management
- Security
- Error detection etc.
39. List the features of a mobile OS.
Ans:
A mobile OS has the following features:
1. Easy to use
2. Good app store
- An app is one of
the basic part of an OS.
- Good and useful
apps forms an important part of an OS.
- The apps should
be simple and interactive.
3. Good battery life
- Power is one of
the main requirement of a smartphone.
- They require
power for processors sensors etc. Therefore, the battery holds a very important
role.
- Smartphones power
usage keeps on increasing therefore, a good battery backup is very essential.
4. Data usage and organization
- An operating
system should focus on controlling the data and network usage. It should keep
the limit and requirement in focus.
- Secondly, the
organization of data related to to-do lists, calendars, alarms, reminders etc
is very important. A good OS should keep this data in a very organized and safe
manner. Moreover, the data should be readily and easily available.
40. What is a kernel?
Ans: A kernel is the core/heart of an OS. It contains all the functions and operations to manage the working of OS.
41. Write the features of JAVA programming language.
OR
Explain the features of Java programming language.
Ans: Java is simple because, its coding style is very clean and easy to understand. It removes complexity because it doesn’t use complex and difficult features of other languages like C and C++.
Usually, a computer language can be either compiled or interpreted. Java integrates the power of Compiled Languages with the flexibility of Interpreted Languages. Java compiler (javac) compiles the java source code into the bytecode. Java Virtual Machine (JVM) then executes this bytecode which is executable on many operating systems and is portable.The most significant feature of Java is that it provides platform independence which leads to a facility of portability, which ultimately becomes its biggest strength.
Being platform-independent
means a program compiled on one machine can be executed on any machine in the
world without any change. Java achieves platform independence by using the
concept of the BYTE code.
Java is robust as it is
capable of handling run-time errors, supports automatic
garbage collection and exception handling, and avoids explicit pointer concept.
Java has a strong memory management system.
It helps in eliminating errors as it checks the code during both compile and
runtime.
Security is an important issue
for any programming language as there is a threat of malicious activities and
viruses. Java supports access modifiers to check memory
access and also ensures that no viruses enter an applet.
Java is a more secure language as compared to C/C++, as it does not allow a programmer to explicitly create pointers. Thus in Java, we can not gain access to a particular variable if we do not initialize it properly.
42. What do
you mean by XML?
Ans: Extensible Markup Language (XML) is a markup language used to describe the
content and structure of data in a document. It is a simplified version of Standard Generalized Markup Language (SGML). XML is an industry standard for
delivering content on the Internet. Because it provides a facility to define
new tags, XML is also extensible.
Like
HTML, XML uses tags to describe content. However, rather than focusing on the
presentation of content, the tags in XML describe the meaning and hierarchical
structure of data. This functionality allows for the sophisticated data types
that are required for efficient data interchange between different programs and
systems. Further, because XML enables separation of content and presentation,
the content, or data, is portable across heterogeneous systems.
43. Explain the concept of XML with an example.
OR
Ans: Extensible Markup Language (XML) is a markup language used to describe the
content and structure of data in a document. It is a simplified version of Standard Generalized Markup Language (SGML). XML is an industry standard for
delivering content on the Internet. Because it provides a facility to define
new tags, XML is also extensible.
Like HTML, XML uses tags to describe content. However,
rather than focusing on the presentation of content, the tags in XML describe
the meaning and hierarchical structure of data. This functionality allows for
the sophisticated data types that are required for efficient data interchange
between different programs and systems. Further, because XML enables separation
of content and presentation, the content, or data, is portable across
heterogeneous systems.
The XML syntax uses matching start and end tags (such
as <name> and </name>) to mark up information.
Information delimited by tags is called an element. Every XML document has a
single root element, which is the top-level element that contains all the other
elements. Elements that are contained by other elements are often referred to
as sub-elements. An element can optionally have attributes, structured as
name-value pairs, that are part of the element and are used to further define
it.
The
following sample XML file describes the contents of an address book:
The root element of the XML file is address_book. The
address book currently contains two entries in the form of person elements:
Jane Doe and John Smith. Jane Doe’s entry includes her address and phone
number; John Smith’s includes his phone and email address. The structure of the
XML document defines the phone element as storing the area code using
the area_code attribute rather than a sub-element in the body of the
element.
44. Why Use XML?
Ans: An industry typically uses data exchange methods that are
meaningful and specific to that industry. With the advent of e-commerce,
businesses conduct an increasing number of relationships with a variety of
industries and, therefore, must develop expert knowledge of the various
protocols used by those industries for electronic communication.
The extensibility of XML makes it a very effective tool for
standardizing the format of data interchange among various industries. For
example, when message brokers and workflow engines must coordinate transactions
among multiple industries or departments within an enterprise, they can use XML
to combine data from disparate sources into a format that is understandable by
all parties.
45. How do you describe an XML
Document?
Ans: An XML (EXtensible Markup Language) Document contains
declarations, elements, text, and attributes. It is made up of entities
(storing units) and it tells us the structure of the data it refers to. It is
used to provide a standard format of data transmission. As it helps in message
delivery, it is not always stored physically, i.e. in a disk but generated
dynamically but its structure always remains the same.
XML
Standard structure and its rules:
Rule 1: Its standard format consists of an XML prolog which contains both XML
Declaration and XML DTD (Document Type Definition) and the body. If the XML
prolog is present, it should always be the beginning of the document. The XML
Version, by default, is 1.0, and including only this forms the shortest
XML Declaration. UTF-8 is the default character encoding and
is one of seven character-encoding schemes. If it is not present, it can result
in some encoding errors.
Syntax of XML Declaration:
<?xml version= “1.0”
encoding= “UTF-8”?>
Syntax of DTD:
<! DOCTYPE
root-element[<!element-declarations>]>
Rule 2: XML Documents must have a root element (the supreme parent element) and its child elements (sub-elements). To have a better view of the hierarchy of the data elements, XML follows the XML tree structure which comprises of one single root (parent) and multiple leaves (children).
46. write an XML
file which will display the book information which include the following:
1. Title of the book 2
2. Author name
3. publisher name
4. edition
5. price
Ans:
XML file
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/css"
href="style.css"?>
<books>
<heading>Welcome To
Book House </heading>
<book>
<title>Title : Web
Programming</title>
<author>Author :
Chrisbates</author>
<publisher>Publisher : Wiley</publisher>
<edition>Edition :
3</edition>
<price> Price :
300</price>
</book>
<book>
<title>Title :
Internet world-wide-web</title>
<author>Author :
Ditel</author>
<publisher>Publisher : Pearson</publisher>
<edition>Edition :
3</edition>
<price>Price :
400</price>
</book>
<book>
<title>Title :
Computer Networks</title>
<author>Author :
Foruouzan</author>
<publisher>Publisher : Mc Graw Hill</publisher>
<edition>Edition :
5</edition>
<price>Price :
700</price>
</book>
<book>
<title>Title : DBMS
Concepts</title>
<author>Author :
Navath</author>
<publisher>Publisher : Oxford</publisher>
<edition>Edition :
5</edition>
<price>Price :
600</price>
</book>
</books>
Stylesheet File: style.css
books {
color: white;
background-color : gray;
width: 100%;
}
heading {
color: green;
font-size : 40px;
background-color : powderblue;
}
heading, title, author, publisher, edition,
price {
display : block;
}
title {
font-size : 25px;
font-weight : bold;
}
47. What Are XSL and XSLT?
Ans: The Extensible Stylesheet Language (XSL) is a W3C standard for describing presentation rules that apply to XML documents. XSL includes both a transformation language, (XSLT), and a formatting language. These two languages function independently of each other. XSLT is an XML-based language and W3C specification that describes how to transform an XML document into another XML document, or into HTML, PDF, or some other document format.
An XSLT transformer accepts as input an XML document and an XSLT document. The template rules contained in an XSLT document include patterns that specify the XML tree to which the rule applies. The XSLT transformer scans the XML document for patterns that match the rule, and then it applies the template to the appropriate section of the original XML document.
48. What are XML’s
advantages over HTML?
Ans: Whereas HTML tells a
browser application how a document should look, XML describes what’s in the
document. In other words, XML is concerned with how information is organized,
not how it is displayed. (XML formatting is done through separate style sheets.)
The HTML
tags are fixed; every site developer uses the same tags to do the same things.
XML, by contrast, lets you create your own tags to label the meaning or use of
data.
XML’s
flexibility has many benefits. It lets you transfer data among corporate
databases and Web sites without losing crucial descriptive information. It lets
you automatically customize the presentation of data rather than display the
same page to all comers. And it makes searches more efficient because search
engines can sort through precise tags rather than long pages of text.
49. How to Embed Audio and Video in
HTML?
Show the use of Audio and Video tag in HTML.
Ans:
Embed Audio in
HTML:
To embed audio in HTML, we use the <audio>
tag. Before HTML5, audio cannot be added to web pages in the Internet
Explorer era. To play audio, we used web plugins like Flash. After the release
of HTML5, it is possible. This tag supports Chrome, Firefox, Safari, Opera, and
Edge in three audio formats : MP3, WAV,
OGG. Only Safari browser doesn’t support OGG audio format.
Syntax:
</audio>
Example:
<!DOCTYPE
html>
<html>
<head>
<title>Page
Title</title>
</head>
<body>
<h2>Click
play button to play audio</h2>
<audio
src="./test.mp3" controls></audio>
</body>
</html>
Embed video in
HTML
To embed video
in HTML, we use the <video>
tag. It contains one or more video sources at a time using <source> tag.
It supports MP4, WebM, and Ogg in
all modern browsers. Only Ogg video format doesn’t support in Safari
browser.
Syntax:
<source src="file_name"
type="video_file_type">
</video>
Example:
<html>
<head>
<title>Page
Title</title>
</head>
<body>
<h2>Click
play button to play video</h2>
<video
src="./test.mp4" controls></video>
</body>
</html>
or you can use the following code:
<!DOCTYPE
html>
<html>
<head>
<title>Page
Title</title>
</head>
<body>
<h2>Click
play button to play video</h2>
<video
controls>
<source
src="./test.mp4">
</video>
</body>
</html>
50. What
are the requirements of Mobile O/S ?
Ans:
- Support for specific communication protocols
- Support for a variety of input mechanisms
- Compliance with open standards
- Extensive library support
51. What
are Special Constraints of Mobile O/S?
Ans:
- Limited memory
- Limited screen size
- Miniature keyboard
- Limited processing power
- Limited battery power
- Limited and fluctuating bandwidth of the wireless medium
52. What is XSL and why it is used.
Ans:
XSL (Extensible Stylesheet Language), formerly
called Extensible Style Language, is a language for creating a style
sheet that describes how data sent over the Web using the Extensible
Markup Language (XML) is to be presented to the user.
In order to understand and style an XML document, World Wide Web Consortium (W3C) developed XSL which can act as XML based Stylesheet Language. An XSL document specifies how a browser should render an XML document. An XSL document specifies how a browser should render an XML document.
53. What is the
purpose of XSLT?
Ans: The XSLT stands for XSL Transformations and XSL stands for eXtensible
Stylesheet Language. The XSLT is used for defining the XML document
transformation and presentations.
XSLT, Extensible Stylesheet Language Transformations,
provides the ability to transform XML data from one format to another
automatically.
54. What is the use
of XML declaration?
Ans: XML declaration is a special tag used to specify the version of XML
used to write the document and optionally some additional meta-information
about the document such as the character set/encoding used. For e.g the syntax
of XML declaration is
<?
XML VERSION=”1.0”?>
55. What is DTD?
Ans: A Document Type Declaration enables an XML parser to verify whether an
XML document is valid, i.e. its elements contain the proper attributes in the
proper sequence.
56. What is well-formed document?
Ans: HTML or XML document is said to
be well formed when it contains elements with proper tagging and no syntactic
errors.
57. Explain
how XML data can be displayed using CSS?
Ans:
Displaying XML Using CSS:
XML stands for Extensible Markup Language. It is a dynamic markup language. It is used to transform data from one form to another form.
An XML file can be displayed using two ways. These are as follows:
1. Cascading Style Sheet
2. Extensible Stylesheet Language
Transformation
Displaying XML file using CSS:
CSS can be used to display the contents of the XML document in a clear and
precise manner. It gives the design and style to whole XML document.
Basic steps in defining a CSS style sheet for XML :
For defining the style rules for the XML document, the following things should
be done:
1. Define the style rules for
the text elements such as font-size, color, font-weight, etc.
2. Define each element either
as a block, inline or list element, using the display property of CSS.
3. Identify the titles and
bold them.
Linking XML with CSS :
In order to display the XML file using CSS, link XML file with CSS. Below is
the syntax for linking the XML file with CSS:
<?xml-stylesheet
type="text/css" href="name_of_css_file.css"?>
58. Create the
XML document to display information of five different books with book name, author,
publisher, price, year of publication.
Ans:
Here, the XML file is created that contains the information
about five books and displaying the XML file using CSS.
XML file:
Creating Books.xml
as:
<?xml-stylesheet
type="text/css" href="style.css"?>
<books>
<book>
<title>Title : Web Programming</title>
<author>Author : Chrisbates</author>
<publisher>Publisher : Wiley</publisher>
<price> Price : 300</price>
<year>Year: 2020</year>
</book>
<book>
<title>Title : Internet world-wide-web</title>
<author>Author : Ditel</author>
<publisher>Publisher : Pearson</publisher>
<price>Price : 400</price>
<year>Year: 2020</year>
</book>
<book>
<title>Title : Computer Networks</title>
<author>Author : Foruouzan</author>
<publisher>Publisher : Mc Graw Hill</publisher>
<price>Price : 700</price>
<year>Year: 2020</year>
</book>
<book>
<title>Title : DBMS Concepts</title>
<author>Author : Navath</author>
<publisher>Publisher : Oxford</publisher>
<price>Price : 600</price>
<year>Year: 2020</year>
</book>
<book>
<title>Title -: Linux Programming</title>
<author>Author -: Subhitab Das</author>
<publisher>Publisher -: Oxford</publisher>
<price>Price -: 300</price>
<year>Year: 2020</year>
</book>
</books>
CSS FILE :
Creating style.css
as:
books {
color: white;
background-color : gray;
width: 100%;
}
heading {
color: green;
font-size :
40px;
background-color : powderblue;
}
heading, title,
author, publisher, edition, price {
display :
block;
}
title {
font-size : 25px;
font-weight :
bold;
}
Difference between 3G and 4G Technology:
Parameters
|
3G Technology
|
4G Technology
|
Full Form
|
The term 3G is
an abbreviation for the third generation technology.
|
The term 4G is
an abbreviation for the fourth generation technology.
|
Maximum Upload
Rate
|
It can go up
to 5 Megabytes per second.
|
It can go much
higher, about 500 Megabytes per second.
|
Maximum Rate
of Download
|
The 3G
technology offers a maximum download rate of about 21 Megabytes per second.
|
The 4G
technology can download videos at a much faster rate, that can go as high as
1 Gigabyte per second.
|
Switching
Techniques
|
It utilises
the packet switching technique.
|
It utilises
both the message switching as well as the packet switching techniques.
|
Range of
Frequency
|
The frequency
of the 3G technology ranges somewhat between 1.8 to 2.5 Gigahertz.
|
The frequency
range of the 4G technology ranges somewhat between 2 to 8 Gigahertz.
|
Network
Architecture
|
The network
architecture of the 3G technology is a wide area cell-based one.
|
The network
architecture of the 4G technology is cell-based for a wide area along with
the integration of WLAN.
|
60. Briefly explain the
differences between GSM and
GPRS.
Ans:
Differences between GSM and GPRS:
|
GSM |
GPRS |
|
GSM stands for Global Systems for Mobile. |
GPRS stands for General Packet Radio Service. |
|
The
frequency bands used in the GSM system
are 900 and 1800 MHz. |
The
frequency bands used in the system
are 850, 900, 1800 and 1900 MHZ. |
|
The type of connection is a circuit-switched network. |
Here the type of connection is a packet-switched network. |
|
It provides data rates of 9.6 kbps. |
It
provides data rates of 14.4 to 115.2 kbps. |
|
SMS (Short Messaging Service) is one of the popular
features. |
MMS (Multimedia Messaging Service) is one of the popular
features. |
|
It takes long time to connect. |
It provides faster connection. |
|
In
GSM, single time slot is allotted to a single
user. |
In
GPRS, multiple time slots can be allotted
to a single user. |
61. Compare
UMTS with WCDMA
Ans:
Comparison between UMTS and WCDMA:
|
Parameters of
Comparison |
UMTS |
WCDMA |
|
Speed |
Faster |
Runs at the speed of
GSM and that is the reason being slower than UMTS. |
|
Technology |
Cellular technology |
Radio technology |
|
Basic channel |
GSM |
CDMA |
|
Coverage area |
Less |
More |
|
Communication devices |
It cannot be used
alone |
Mostly used in all
phones, but it is combined with GSM or UMTS in some cases. |
62. Compare IOS with
Android OS.
Ans:
Comparison
between Android and iOS:
|
Parameters of
Comparison |
Android |
iOS |
|
Owned by |
Google LLC |
Apple Inc. |
|
Created by |
Android Inc. |
Apple Inc. |
|
Mainly developed by |
Google and Open Handset Alliance |
Apple |
|
Launched on |
23
September 2008 |
29 June 2007 |
|
Used in |
Mobiles, tablets, gaming consoles, smart TVs, etc. |
iPhone, iPad, iPod Touch, iPod Nano, and Apple TV |
|
Virtual assistant |
Google Assistant |
Siri |
|
Type of software |
Open Source |
Closed Source |
|
Languages used (programming) |
C, Java, C++, and others |
Swift, Objective-C, C++, and others |
|
Kernel used |
Linux |
XNU hybrid |
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