GATE CSE 2020 | Question: 19

Question

A multiplexer is placed between a group of $32$ registers and an accumulator to regulate data movement such that at any given point in time the content of only one register will move to the accumulator. The number of select lines needed for the multiplexer is ______.

Answer 1

If there are $\text{‘}m\text{’}$ select lines for a multiplexer, then it may have up to $2^m$ input lines.

Given that there are $32$ input lines. So, there must be $\left \lceil \log_2 n \right \rceil = ⌈\log_2 {32}⌉ =5$ select lines.

Comments

@Shaik Masthan You can use \log in LaTeX for logarithm, which displays better. 

Answer 2

5

In multiplexer 2^m input lines  means m select lines and 1 out put 

Multiplexer

More questions ECE 

http://www.gatepaper.in/2014/11/previous-gate-questions-on-multiplexers.html?m=1