Computer Knowledge

Operating Systems

1,344 Questions

Test your computer knowledge with these questions on operating systems. The content covers various platforms including Unix, Linux, Windows, Android, and Macintosh. These questions are commonly asked in the computer knowledge sections of banking and government exams.

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Operating Systems Questions

Multiple choice

__________ method creates only one preference file for the activity.

  1. getSharedPreferences()

  2. getPreferences()

  3. Both (1) and (2)

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The getPreferences() method (called without a name parameter) creates a single preferences file specific to that activity. In contrast, getSharedPreferences() requires a name parameter and can be shared across different activities or components.

Multiple choice

No permission is needed to store data in

  1. shared preferences

  2. internal storage

  3. external storage

  4. Both (1) and (2)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

SharedPreferences and internal storage are private to each application and reside in the app's sandbox, so they require no special permissions. External storage does require permissions (though the exact permissions have changed across Android versions - WRITE_EXTERNAL_STORAGE, READ_EXTERNAL_STORAGE, or scoped storage in newer APIs).

Multiple choice

getExternalStorageDirectory()method returns sdcard location that

  1. is same for all devices

  2. may vary for different devices

  3. is Mnt/sdcard

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The external storage directory path varies across devices - different manufacturers use different mount points (e.g., /mnt/sdcard, /sdcard, /storage/emulated/0). Developers should never hardcode paths and should always use the Environment.getExternalStorageDirectory() API or the Storage Access Framework for compatibility.

Multiple choice

Which of the following is the correct syntax to start an explicit activity?

  1. Intent intent = new Intent(MyActivity.this, MyOtherActivity); startActivity(intent);

  2. Intent intent = new Intent(MyActivity.this, MyOtherActivity.class); startActivity(intent);

  3. Intent intent = new Intent(MyActivity.class, MyOtherActivity.class); startActivity(intent);

  4. Intent intent = new Intent(this, MyOtherActivity.this); startActivity(intent);

  5. Intent intent = new Intent(MyOtherActivity.class); startActivity(intent);
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

After calling startActivity, the new activity, i.e. MyOtherActivity will be created and will move to the top of the activity stack.

Multiple choice

Match the callback methods in an activity class with their description.

(a) onCreate() 1. It is called when the first activity is created.
(b) onStart() 2. It is called when activity restarts after stopping it.
(c) onResume() 3. It is called before the activity is destroyed by the system.
(d) onPause() 4. It is called when the activity is no longer visible.
(e) onStop() 5. It is called when the activity becomes visible to the user.
(f) onDestroy() 6. It is called when the user starts interacting with the application.
(g) onRestart() 7. When It is called, the paused activity does not receive any further user input and cannot execute any code.

  1. a – 1; b – 5; c – 6; d – 7; e – 4; f – 3; g – 2

  2. a – 2; b – 5; c – 6; d – 7; e – 4; f – 3; g – 1

  3. a – 2; b – 4; c – 6; d – 7; e – 5; f – 3; g – 1

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

.

Multiple choice

Which of the following statements is/are correct?

A. The getCount() returns the number of items in the pages. B. The. getItem() returns the fragment at the specified position.

  1. Only A

  2. Only B

  3. Both A and B

  4. Neither A nor B
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The getCount() returns the total number of fragments in the pages and the getItem() returns the fragment at the specified position.This method will be called as the user scrolls through the pages.

Multiple choice

Which of the following methods is not provided by AsyncTask?

  1. doInBackground()

  2. doInFront()

  3. onPreExecute()

  4. onPostExecute()
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Following are the methods provided by AsyncTask: doInBackground(), onPreExecute(),onPostExecute(), onProgressUpdate(), isCancelled(). There is no method called doInFront() provided by AsyncTask.