Question

The output of a $2$ input OR gate is $0$ only when its.

• A. Both inputs are $0$
• B. Either inputs is $1$
• C. Both inputs are $1$
• D. Either input is $0$
• E. None of the above

Answer 1

The correct option is A Both inputs are $0$

The output of a 2 input OR gate is 0 only when its Both inputs are 0.

This circle is known as an “inversion bubble” and is used in NOT, NAND and NOR symbols at their output to represent the logical operation of the NOT function. This bubble denotes a signal inversion (complementation) of the signal and can be present on either or both the output and/or the input terminals.

To symbolize this output signal inversion, the NAND gate symbol has a bubble on the output line. The truth table for a NAND gate is as one might expect, exactly opposite as that of an AND gate: As with AND gates, NAND gates are made with more than two inputs.