Which of the following units denotes the dimensions $\frac{M L^2}{Q^2}$,where $Q$ denotes the electric charge?

$A$ copper wire is wound on a wooden frame,whose shape is that of an equilateral triangle. If the linear dimension of each side of the frame is increased by a factor of $3$,keeping the number of turns of the coil per unit length of the frame the same,then the self-inductance of the coil:

The current $(I)$ in an inductor is varying with time $(t)$ as shown in the figure. Which of the following graphs shows the correct variation of voltage $(V)$ with time $(t)$ in the inductor?

$A$ coil is wound on a core of rectangular cross-section. If all the linear dimensions of the core are increased by a factor of $2$ and the number of turns per unit length of the coil remains the same, the self-inductance increases by a factor of (Assume, permeability is same).

$A$ hollow cylinder has length $l$,radius $r$,and thickness $d$,where $l >> r >> d$,and is made of a material with resistivity $\rho$. $A$ time-varying current $I$ flows through the cylinder in the tangential direction. Assume the current is always uniformly distributed along the length of the cylinder. The cylinder is fixed so that it cannot move; assume that there are no externally generated magnetic fields during the time considered for the problems below. Assume current at $t = 0$ to be $I_0$. What is the current $I(t)$ for $t > 0$?

$A$ coil of self-inductance $L$ is connected in series with a bulb and an a.c. source. Brightness of the bulb decreases when