GATE CSE 2000 | Question: 2.13

Question

A graphics card has on board memory of $1$ MB. Which of the following modes can the card not support?

• A. $1600 \times 400$ resolution with $256$ colors on a $17$ inch monitor
• B. $1600 \times 400$ resolution with $16$ million colors on a $14$ inch monitor
• C. $800 \times 400$ resolution with $16$ million colors on a $17$ inch monitor
• D. $800 \times 800$ resolution with $256$ colors on a $14$ inch monitor

Comments

Out of syllabus

Answer 1

Just measure the memory required for the given resolution. The screen size has nothing to do with the memory required and is given just for the sake of it. Each pixel is represented using a color. So, we need to find the number of pixels and multiply by the amount of storage required for color.

A. 256 colors means 8 bits for color representation meaning 1 byte. So, 1600 * 400 resolution requires 640 kB. We have 1 MB, so fine.

B. 16 million colors require 24 bits or 3 bytes. So, 1600 * 400 resolution requires 640 k * 3 = 1920 kB which is over our on board memory. So, not possible.

C. Again 3 bytes for a color. 800 * 400 resolution requires 320 k * 3 = 960 kB which is fine as we have 1 MB on board.

D. 256 colors require 1 byte. 800 * 800 resolution requires 640 k * 1 = 640 kB which is again fine.

So, answer is B.

Comments

B=640k ...?

What is B?

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@Arjun Sir

Why 1KB is not equal to 1024 Bytes here... Please tell the cases where 1K= 1000 units and where 1K = 1024

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Will the number of bits required for color representation always be a multiple of 8?