The end correction for the vibrations of air column in a tube of circular cross-section will be more if the tube is

The potential difference $\left(V_A-V_B\right)$ between the points ' $A$ ' and ' $B$ ' in the given part of the circuit is

The logic gate represented by following logic circuit is

A coil of ' $n$ ' turns and radius ' $R$ ' carries a current 'I'. It is unwound and rewound to make a new coil of radius $\frac{R}{3}$ and the same current is passed through it. The ratio of the magnetic moment of the new coil to that of the original coil is