Assertion: Ohm's law cannot be applied to $a.c.$ circuits.
Reason: Resistance offered by a capacitor for an $a.c.$ source depends upon the frequency of the source.

Assertion: Long distance power transmission is done at high voltage.
Reason: At high voltage supply, power losses are less.

In an $AC$ circuit, the instantaneous current is zero when the instantaneous voltage is maximum. In this case, the source may be connected to:
$A$. Pure inductor.
$B$. Pure capacitor.
$C$. Pure resistor.
$D$. Combination of an inductor and capacitor.
Choose the correct answer from the options given below:

The coil of an $A.C.$ generator has $100$ turns, each of cross-sectional area $2 \, m^2$. It is rotating at a constant angular speed of $30 \, rad/s$ in a uniform magnetic field of $2 \times 10^{-2} \, T$. If the total resistance of the circuit is $600 \, \Omega$, then the maximum power dissipated in the circuit is: (in $W$)

If $L, C$ and $R$ represent inductance,capacitance and resistance respectively,then which of the following does not represent the dimensions of frequency?

The figure shows a system of an inductor and a parallel plate capacitor made of $2$ parallel circular plates of area $A$,filled with a dielectric liquid of dielectric constant $K$. $A$ small leak develops in the capacitor,and the liquid starts to fill the inductor of the same dimensions having $n$ turns per unit length. Find the ratio of the magnitude of the initial reactance to the final reactance of the circuit after the liquid fills the inductor completely.
Given: $\omega^2 A^2 n^2 = c^2$
$\omega \rightarrow$ angular frequency of $AC$
$c \rightarrow$ speed of light
$\mu_r \rightarrow$ relative permeability of the liquid