How many select lines are required for an 8-to-1 multiplexer?

Correct Answer (Detailed Explanation is Below)

B. 3

Detailed Explanation

Explanation:

For an 8-to-1 Multiplexer (MUX):

• A multiplexer selects one input out of many inputs and sends it to the output.

• Number of select lines (n) required is calculated by:

$$2^S = \text{Number of Inputs}$$

For 8 inputs:

$$2^S = 8$$$$S = 3$$

So 3 select lines are needed.