Question

The output of an 'OR' gate is 'one'

• A. if both inputs are zero
• B. if either or both inputs are '1'
• C. if only both inputs are '1'
• D. if either input is zero

Hint:

An 'OR' gate represents logical addition ($A + B = Y$). As long as there is a '1' anywhere in the inputs, the sum will be treated as high ('1'). The only way to get a '0' is if all inputs are '0'.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
We must identify the logical condition under which a standard 2-input OR gate produces a high ('1') output.

Step 2: Detailed Explanation:
Let's review the truth table for an OR gate with inputs A and B and output Y:
1. If A = 0, B = 0 $\implies$ Y = 0
2. If A = 0, B = 1 $\implies$ Y = 1
3. If A = 1, B = 0 $\implies$ Y = 1
4. If A = 1, B = 1 $\implies$ Y = 1
From the truth table, the output is '1' whenever at least one of the inputs is '1'. This covers the case where either input is '1' or both inputs are '1'.

Step 3: Final Answer:
The output is 'one' if either or both inputs are '1', matching option (B).