Digital Electronics MSQ - Physics MCQ

A demultiplexer sends a single input to multiple outputs, depending on the select lines. Demultiplexer converts single input into multiple outputs.

The realization of the algebraic expression   in terms of logic gate is

Truth table.

Hence, (a), (c), (d)
The correct answers are: P = 0, Q = 0, R = 0, P = 1, Q = 0, R = 1, P = 1, Q = 1, R = 0

Hence, it is an integrator and a low-pass filter.
The correct answers are: Integrator, Low-pass filter

Output is HIGH when only one of the input is high.
The correct answers are: It goes HIGH at t = 0 and back LOW at t = 0.8 ms, It goes HIGH at t = 1 ms and back LOW at t = 3 ms

Truth table is,

This is truth table for NAND gate.

The gate whose output is low if and only if all inputs are high, is NAND.

The logic NAND gate is a combination of a digital logic AND gate and a NOT gate connected together in series.

A NAND gate (NOT-AND) is a logic gate which produces an output which is false only if all its inputs are true; thus its output is complement to that of an AND gate. A LOW (0) output results only if all the inputs to the gate are HIGH (1); if any input is LOW (0), a HIGH (1) output results.

If either V₁ or V₂ is high, we get a high in output, hence it each like an OR gate.
The correct answers are: NAND gate for a negative logic system, AND gate for a positive logic system, AND gate for a negative logic system

The truth table for XOR gate is

(b), (c), (d).
The correct answers are:

 clearly it follows OR gate. 


Thus, it also follows NAND gate 
  it is an AND gate 
 it is not a NOR gate. 
Therefore, the correct options are (b, c)
The correct answers are: NAND, OR

A NAND gate is given by Truth table is.

It is low when both input signals are high otherwise it goes high.
The correct answers are: goes low at t = 0.8 ms, comes back high at t = 1 ms