Question

A long corridor has a single light bulb and two doors with light switch at each door.

Design logic circuit for the light; assume that the light is off when both switches are
in the same position

Answer 1

The answer is below

Step-by-step explanation:

Let A represent the first switch, B represent the second switch and C represent the bulb. Also, let 0 mean turned off and 1 mean turned on. Since when both switches are in the same position, the light is off. This can be represented by the following truth table:

A B C (output)

0 0 0

0 1 1

1 0 1

1 1 0

The logic circuit can be represented by:

C = A'B + AB'

The output (bulb) is on if the switches are at different positions; if the switches are at the same position, the output (bulb) is off. This is an XOR gate. The gate is represented in the diagram attached below.