In the circuit, the logical value of A = 1 or B = 1 when potential at A or B is 5 V and the logical value of…

When both $A$ and $B$ have logical value ‘$1$’ both diode are reverse bias and current will flow in resistor hence output will be $5$ volt i.e. logical value ‘$1$’.

In all other case conduction will take place, hence output will be zero volt i.e. logical value ‘$0$’. So truth table is

$\begin{array}{ccc}A& B& Y\\ 0& 0& 0\\ 0& 1& 0\\ 1& 0& 0\\ 1& 1& 1\end{array}$

Thus, given circuit is equivalent to an AND gate.