The following truth table corresponds to which logic gate?
$A: 0, 0, 1, 1$
$B: 0, 1, 0, 1$
$X: 0, 1, 1, 1$

The output of the circuit is low (zero) for: $(A) \ X = 0, Y = 0$,$(B) \ X = 0, Y = 1$,$(C) \ X = 1, Y = 0$,$(D) \ X = 1, Y = 1$. Choose the correct answer from the options given below:

The truth table for the following logic circuit is:

Which of the following is the Boolean expression for a $NOR$ gate?

Identify the equivalent logic gate represented by the given circuit.

The circuit diagram shows a logic combination. Initially, for inputs $P, Q, R$ and $S$ all at state $1$, the outputs are $X=1, Y=1$ and $Z=0$. When inputs $P$ and $R$ change to state $0$ while inputs $Q$ and $S$ remain at state $1$, what are the new states of outputs $X, Y$ and $Z$?