Logic Gates

IMPORTANT

Logic Gates: Overview

This topic covers concepts such as Types of Signals, Analogue Signals, Digital Signals, Logic Gates, Truth Table in Logic Gates, The NOT Gate, The OR Gate, The AND Gate, The NAND Gate, The NOR Gate, and The XOR Gate.

Important Questions on Logic Gates

EASY
IMPORTANT

The same input signal is applied to both the (input) terminals of a given logic gate.

If the output is the(i) same as the (common) input signal

(ii) inverted with respect to the (common) input signal,

Identify the logic gate/s involved in each case.
Question Image

HARD
IMPORTANT

Write down the output at X for the inputs A=0,B=0 and A=1, B=1
Question Image

EASY
IMPORTANT

Identify the logic gates marked P and Q in the given logic circuit.

Question Image

EASY
IMPORTANT

Identify the logic gates marked P and Q in the given logic circuit.
Question Image

EASY
IMPORTANT

(i) Identify the logic gates marked P and Q in the given logic circuit.

Question Image

EASY
IMPORTANT

The inputs A and B are inverted by using two NOT gates and their outputs are fed to the NOR gate as shown below.
Question Image

Analyse the action of the gates (1) and (2) and identify the logic gate of the complete circuit so obtained.

MEDIUM
IMPORTANT

Which of the following flip-flops does not have race problem?

EASY
IMPORTANT

The truth table of a certain logic circuit is shown below.

A (input) B (input) Y (output)
0 0 0
0 1 1
1 0 1
1 1 0

The logic gate represented by the above truth table belongs to

MEDIUM
IMPORTANT

A digital signal possesses:

EASY
IMPORTANT

Where is NOR gate used?

EASY
IMPORTANT

What is the expression of XNOR gate?

EASY
IMPORTANT

How do you write a NOR gate?

EASY
IMPORTANT

Is NOR the same as and?

EASY
IMPORTANT

Is NOR gate and XOR gate same?

EASY
IMPORTANT

Digital signals have ________ noise immunity compared to the analog signals.

EASY
IMPORTANT

Sine wave is a fundamental 

HARD
IMPORTANT

In the given circuit, the input voltages at P and Q could be either 0 V or 10 V. Use the fact that a diode under forward bias is a short circuit, and under reverse bias is an open circuit. The truth table of the circuit will be that of

Question Image

EASY
IMPORTANT

Identify the gate and match A,B,Y in the bracket to check.

    Question Image

EASY
IMPORTANT

The combinations of NAND gates shown here (in the figure) are equivalent to
 Question Image

EASY
IMPORTANT

If a, b, c, d are inputs to a gate and x is its output, then, as per the following time graph, the gate is:
Question Image