Question

Express the following circuit in the symbolic form. Prepare the switching table:

Answer 1

Let p: the switch S₁ is closed
      q: the switch S₂ is closed
       r: the switch S₃ is closed
Then the symbolic form of the given statement is:
(p∨q) ∧ (p∨q)

Switching Table

p	q	r	p∨q	p∨r	(p∨q) ∧ (p∨q)
1	1	1	1	1	1
1	1	0	1	1	1
1	0	1	1	1	1
1	0	0	1	1	1
0	1	1	1	1	1
0	1	0	1	0	0
0	0	1	0	1	0
0	0	0	0	0	0