Which of the following represents a $NAND$ gate?

For the given circuit,what will be the truth table for the output $Y$ based on all possible inputs $A$ and $B$?

Two car garages have a common gate which needs to open automatically when a car enters either of the garages or cars enter both. Devise a circuit that resembles this situation using diodes.

In the following logic circuit,the sequence of the inputs $A, B$ are $(0, 0), (0, 1).$ The output $Y$ for this sequence will be

For the given logic circuit,what should be the value of input $ABC$ to get an output $Y = 1$?

To get an output $Y = 1$ in the given circuit,which of the following inputs will be correct?