Digital Electronics - Number Systems and Codes - Discussion

Discussion Forum : Number Systems and Codes - General Questions (Q.No. 10)
10.
If a typical PC uses a 20-bit address code, how much memory can the CPU address?
20 MB
10 MB
1 MB
580 MB
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
13 comments Page 1 of 2.

Briano said:   6 years ago
@All.

So, MB is quite different from Mb?
Buy how do you pronounce it?
MB - Megabits
Mb - Megabytes.

Anyone clear my doubt.
(1)

Ryan said:   6 years ago
I agree @Rama. Thanks.
(1)

Rama Krishna Sambari said:   8 years ago
Bit is denoted as 'b'.
Byte is denoted as 'B'.

20 bits = 20b.
2^20 = 2^20 * 2^10 = 1024b * 1024b = 1Kb * 1Kb = 1Mb.

The answer is 1Mb not 1MB.
(2)

PETAK said:   8 years ago
2 is used as the base because computer operates in binary, i.e. powers of 2.

Nitish kumar said:   10 years ago
2^20 memory locations can be addressed but it can not measured in mb. Size of memory will depend upon size of data bus.

Kiran said:   1 decade ago
Because computer works with only binary numbers {0, 1}. So that radix is 2.

That's why base is 2?

Niki said:   1 decade ago
Why have we taken 2 as the base, can anyone explain?

Lalit said:   1 decade ago
The answer is very simple. We know 1024 bytes is 1 kb and 2^10 is 1024, hence 2^10 * 2^10 =2^20, that is 1024 *1024, 1kb*1024 is equal to 1 Mb.

Ashwani said:   1 decade ago
2^20 = 2^10*2^10.

As 2^10 = 1Kb,
Hence 2^20 = 1Kb*1Kb = 1Mb.

Sukesh said:   1 decade ago
Address bus is 20bits so 2^20=1Mb used in 8086 microprocessor.


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