Combined 2 Banks Senior Officer (IT) Exam: 2020প্রশ্ন ও সমাধান

Correct answer: (b) do-while

A menu program has to display the menu and read the user's choice at least once, then repeat until the user picks "Exit". A do-while loop fits this exactly: its body runs first and the condition is tested only after each pass, so the menu always appears once with no extra setup.

int choice;
do {
    printf("1. Add  2. Delete  0. Exit\n");
    scanf("%d", &choice);
    /* handle the choice, usually with switch */
} while (choice != 0);

choice gets its value inside the body before the test, so the condition never reads an uninitialised variable.

Why the other options are wrong

• (a) while: Tests the condition before the body, so choice must be given a value before the loop (or the menu code repeated). It works, but less naturally.
• (c) for: Also tests first, and is meant for counter-controlled repetition, not "repeat until the user quits".
• (d) switch: A selection statement that handles the chosen item. It repeats nothing, so it is not a loop at all.

Tip: "Show at least once, then ask whether to repeat" → do-while.

Source: do-while loop - cppreference.com; Statements - cppreference.com

Correct answer: (d) All of the above

PowerPoint lets you place both pictures and sound on a slide. JPEG (.jpg) photos and GIF (.gif) images, including animated GIFs, are inserted through Insert → Pictures, exactly like any other picture file. WAV (.wav) is on Microsoft's list of supported audio formats for PowerPoint, alongside .m4a, .mp3 and .aac. Since every listed format can be added, the answer is "All of the above".

Why the other options are wrong

• (a) .jpg: correct on its own, but incomplete, because .gif and .wav can be added too.
• (b) .gif: also supported, but choosing only this one ignores .jpg and .wav.
• (c) .wav: a supported audio format, but the pictures (.jpg, .gif) are supported as well.

Tip: When every single option is individually true, the answer is "All of the above"; check each option before ticking one.

Source: Audio and video file formats supported in PowerPoint (Microsoft Support); Add an animated GIF to a slide (Microsoft Support)

Correct answer: (b) satoshis

The smallest unit of bitcoin recorded on the blockchain is the satoshi (sat), named after Bitcoin's pseudonymous creator, Satoshi Nakamoto.

• 1 BTC = 100,000,000 sat = 10⁸ sat
• 1 sat = 1 ÷ 10⁸ BTC = 0.00000001 BTC

Why the other options are wrong

• (a) unit coin: There is no Bitcoin unit with this name.
• (c) Ethereum: A separate blockchain platform with its own currency (ether), not a unit of bitcoin.
• (d) litecoin: A separate cryptocurrency, not a fraction of a bitcoin.

Tip: 1 bitcoin = 100 million satoshis; one satoshi is the 8th decimal place of a bitcoin.

Source: Vocabulary - Bitcoin (bitcoin.org)

Correct answer: (c) Address hazard

Pipeline hazards are situations that stop the next instruction from proceeding in its planned clock cycle. There are exactly three classes:

• Structural (resource) hazard: two instructions need the same hardware unit at the same time.
• Data hazard: an instruction needs a result that an earlier instruction has not produced yet.
• Control hazard: the next instruction to fetch depends on a branch whose outcome is not yet known.

"Address hazard" is not one of them.

Why the other options are wrong

• (a) Resource hazard: another name for a structural hazard, so it is a real pipeline hazard.
• (b) Control hazard: a real hazard caused by branches and jumps.
• (d) Data hazard: a real hazard caused by data dependences (RAW, WAR, WAW).

Tip: Remember S-D-C: Structural (resource), Data, Control.

Source: Lecture 9: Pipeline Hazards (Stanford EE 108B)