Mid-Sem Exam Mobile Computing Nptel

Mid-sem Exam

For all the questions till Intent.

1. What is not true about an Activity

 always contains a user interface.

 talks to other activities using intents

 has multiple lifecycle states.

 goes to paused state when completely hidden.

1 point

   2. What is not a major component of an Android App.

 Service

 Activity

 Bakground Receiver

 Intent

1 point

 3. What is not a major component of an Android App.

 Service

 Activity

 Bakground Receiver

 Intent

1 point

4. Which of the following is the parent class of Activity?

 Object

 Context

 ActivityGroup

 ContextThemeWrapper

1 point

5. Which of the following is not a type of UI layout.

 Frame layout

 Grid view

 List view

 Horizontal layout

1 point

6. In which of the following layouts, the position of a UI element depends on the position of other UI elements.

 List view

 Linear layout

 Absolute layout

 Relative layout

1 point

7. What is the importance of Hierarchy Viewer?

 Provides a visual representation of layout’s view hierarchy.

 Monitor the sequence of intents.

 Helps you discover bottlenecks in the layout performance.

 None of the above.

1 point

8. Which of the following layout designs can be optimised for a better performing UI?

 A layout that has no children or no background.

 A deeply nested layout.

 A layout with children that has no siblings, is not a ScrollView or a root layout, and does not have a background.

 All of the above.

1 point

9. What is the drawback of using ‘in’ (inches) as the unit of padding?

 Padding value scales itself proportionate to the size of screen.

 Padding value does not scale across different screen sizes.

 We get more precision compared to other units like px, dp etc.

 None of the above

1 point

10.Which of the following layouts has the layout_weight property?

 Relative layout

 Table layout

 List view

 None of the above

1 point

11. Which of the following layouts is often used to display dynamic enumerated data?

 Linear layout

 List view

 Relative layout

 Table layout

1 point

12. What happens when a button is clicked but its onClickListener is not defined?

 App will crash.

 A toast will be displayed.

 Nothing will happen.

 Wrong question, the button would not appear in the UI.

1 point

13. What is the correct sequence of execution of android activity lifecycle methods when the screen is rotated?

 onCreate(), onStart(), onResume()

 onPause(), onStop(), onDestroy(), onCreate(), onStart(), onResume()

 onDestroy(), onCreate(), onStart(), onResume()

 None of the lifecycle methods will be invoked.

1 point

14.Suppose you have logged into a game using your gmail id and your gmail app running in the background crashes, what will happen?

 The game will also crash.

 Nothing happens to the game that is purely the outcome of the gmail app crash.

 You cannot login/logout of the game.

 You will be automatically logged out from the game due to crashing of the gmail app.

1 point

Which of the following app components are not activated by intents?

 Activities

 Services

 Content providers

 Broadcast receivers

1 point

Which of the following is true when an app (A) starts another app’s (B) component?

 An app cannot run another app’s components.

 B’s component runs in the process in which A is running.

 Both A and B should be running in the same process.

 B’s component runs in B’s process.

1 point

Which of the following is true:

 An android app execution starts from the function ‘main()’.

 Apps running on different processes can directly activate each other’s components.

 Android OS shuts down when it goes out of memory.

 None of the above

1 point

Which of the following is true about android manifest file?

 It defines the UI elements of each activity.

 It cannot force an orientation to an activity.

 It describes all the components of the application.

 None of the above

1 point

Which of the following can be a sequence of android lifecycle methods?

 onPause(), onStart(), onResume()

 onRestart(), onStart(), onResume()

 onPause(), onStop(), onDestroy(), onRestart()

 None of the above.

1 point

An activity never resides in which of the following states?

 Created

 Stopped

 Destroyed

 Resumed

1 point

Which of the following will definitely trigger onDestroy() method?

 finish() method

 Android OS destroys the process in which the app was running

 Current app leaves the foreground completely.

 App is killed

1 point

Which of the following is not a logcat method? (ignore function parameters)

 Log.v()

 Log.i()

 Log.wtf()

 Log.a()

1 point

What is the purpose of adding padding to a UI element?

 It separates the element from elements outside it.

 Moves contents of an element away from its edges.

 Both A and B

 None of the above

1 point

What is the structure of extra information (Bundle) passed while starting a new activity?

 List

 Integer

 Key-value pair

 String

1 point

What will happen if a TextView variable is assigned the type View?

 App will not compile.

 App will crash

 TextView will work fine

 Nothing will be displayed

1 point

How do we ensure backward compatibility (smartly) of the app?

 Running on all the phones; old and new

 Only compiling for the latest Android SDK

 Disable some features of the app using newer Android Versions

 Specifying minSDK version

1 point

What is a callback?

 A function that is called when the app stops.

 A function that is called when an event occurs.

 All of the these.

 A function that is called when the app starts.

1 point

Which if the following can be used to detect errors in the app?

 Gradle

 Logcat

 OnClickListener

 None

1 point

Which Exception is thrown when you try to access the index -1 in a List?

 IOException

 NullPointerException

 Compilation error

 No exception will be thrown

1 point

What will happen if an id R.id.something is not specified in the XML, but accessed in the source code?

 App will crash/not compile.

 A message will displayed.

 Nothing will happen.

 The View will work fine without any problems.

1 point

Where should the images be normally stored in a project?

 src

 AndroidManifest.xml

 res/layout

 res/drawable

1 point

Which of the following is NOT a type of an intent?

 Exhaustive Intent

 Explicit Intent

 Implicit Intent

 None of these

1 point

What is the process of displaying the fields present in the layouts?

 Inflating

 Overriding

 Bundle attaching

 None of these

1 point

How many levels of Log labels are there?

 3

 4

 5

 6

1 point

Which of the following is NOT specified in AndroidManifest.xml?

 Global Variables

 Permissions

 Activities

 Services

1 point

Is it a good practice to have one icon of fixed resolution?

 No, we need icons for different pixel density screens

 No, android takes care of it

 Yes

 None

1 point

Which of the following is used to restore information when the app is destroyed?

 String savedInstanceState

 Integer savedInstanceState

 ArrayList sacedInstanceState

 Bundle savedInstanceState

1 point

Which of the following is NOT true

 @Override is used to change definition of a function

 Not all methods of an interface need to be redefined

 An Interface and abstract class are not the same

 A class can inherit another class as well as implement any interface

1 point

What happens when a button is present in the source code but its XML is not defined?

 App will crash/not compile.

 A message will displayed.

 Nothing will happen.

 The button would appear in the UI.

1 point

Which of these is not a part of the APK?

 Resources

 Dalvik Executable

 A and B

 None of the above

1 point

How can you prevent your app from showing ANR messages?

 Kill the application process periodically

 Create a child thread where expensive computations are done

 A and B

 None of the above

1 point

Which data structure is used when a new activity is opened?

 List

 Queue

 Priority queue

 Stack

1 point

Many of you must have used an Android emulator to test your applications. Which of the following statements are true about the emulator?

 The emulator runs your application the same way as your phone

 The emulator is only a virtual machine

 An emulator is exactly same as a simulator

 An emulator can emulate sensors of the phone

1 point

In exception handling, what is the difference between “throw” and “throws”?

 It is the same thing

 “throw” is used to explicitly throw an exception and “throws” is used to declare an exception

 You can declare multiple exceptions with “throw” but you cannot do that with “throws”

 None of the above

1 point

Which of the following statements are false?

 Multiple activities can be running at a given point in time

 Only one activity can be running at a given point in time

 ContentProvider connects code running in one process to data in another process

 A and C

1 point

Which of the following statements are true?

 The receiver type is mentioned by the sender in an explicit intent

 Activity is always stopped before being destroyed

 When an activity is in stopped state, it does nothing

 All statements are false

1 point

Which of the following are true about interfaces in Android?

 An interface has a constructor

 An interface cannot be instantiated

 Interface exists in the layout.xml file

 All statements are true

1 point

What will happen if you have an infinite loop running in your application?

 Phone will shut down

 App will crash immediately

 The app will freeze and crash after sometime

 Android will not let the loop run

1 point

Which of the following statements are true about intents?

 Intents are used for starting new activities and services

 Intents are asynchronous

 A and B

 None of the above

1 point

What will happen if you use ListView and keep increasing the size of the list?

 Nothing, app will work fine

 App will become slow eventually

 Android OS will crash

 None of the above

1 point

How many types of orientations (like landscape and horizontal) does Android Support?

 2

 3

 4

 1

1 point

Which of the following statements is false?

 App permissions are contained in the Android Manifest

 The layout.xml file contains strings used in the app

 The layout.xml file contains the code which is used to run the app

 B and C

1 point

Is it possible to have an Activity without UI in Android?

 Yes, it is possible!

 No, it cannot be done because all activities need to have a UI compulsorily

 Sometimes possible, sometimes not possible

 None of the above

1 point

After an application is installed, where is it stored?

 External memory

 Sandbox

 Internal memory

 Phone databas

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