GATE 2005-IT

Question 10

A two-way switch has three terminals a, b and c. In ON position (logic value 1), a is connected to b, and in OFF position, a is connected to c. Two of these two-way switches S1 and S2 are connected to a bulb as shown below.

Which of the following expressions, if true, will always result in the lighting of the bulb ?

A
B
C
D

Digital-Logic-DesignCircuits-Output

Question 10 Explanation:

The bulb will be on when both the switch S1 and S2 are in same state, either OFF (or) ON:

From this we can clearly know that given is EX-NOR operation i.e.,
(S1⊙S2) = (S1⊕S2)’

Correct Answer: C

Question 10 Explanation:

The bulb will be on when both the switch S1 and S2 are in same state, either OFF (or) ON:

From this we can clearly know that given is EX-NOR operation i.e.,
(S1⊙S2) = (S1⊕S2)’