If $A$ and $B$ are two inputs in an $AND$ gate,then the $AND$ gate has an output of $1$ when the values of $A$ and $B$ are:

$A$ combination of logic gates is as shown in the figure. $P$,$Q$,$R$,and $S$ are the inputs and $X$,$Y$,and $Z$ are outputs. When inputs $P$ and $R$ are 'low' $(0)$ and $Q$ and $S$ are 'high' $(1)$,the outputs $X$,$Y$,and $Z$ are respectively:

Write the symbol,truth table,function,and Boolean equation for $NOT$,$AND$,and $OR$ gates.

The figure below shows a combination of $NOT$ gates and a $NOR$ gate. The combination is equivalent to:

The logic behind the $NOR$ gate is that it gives

Which of the following relations is correct according to Boolean algebra?