An $L-C$ resonant circuit contains a $400 \ pF$ capacitor and an inductor of $400 \ \mu H$. It is coupled to an antenna. The wavelength of the radiated electromagnetic wave is:

$A$ $60\,\mu F$ capacitor is charged to $50\, V$. This charged capacitor is connected across a $1.5\, mH$ coil,so that $LC$ oscillations occur. The max current in the coil is......$A$

What are $LC$ oscillations?

At a moment $t = 0$ when the charge on capacitor $C_1$ is zero,the switch $S$ is closed. If $I_0$ is the current through the inductor at that instant,then for $t > 0,$

An $LC$ circuit contains a $20 \; mH$ inductor and a $50 \; \mu F$ capacitor with an initial charge of $10 \; mC$. The resistance of the circuit is negligible. Let the instant the circuit is closed be $t=0$.
$(a)$ What is the total energy stored initially? Is it conserved during $LC$ oscillations?
$(b)$ What is the natural frequency of the circuit?
$(c)$ At what time is the energy stored $(i)$ completely electrical (i.e.,stored in the capacitor)? $(ii)$ completely magnetic (i.e.,stored in the inductor)?
$(d)$ At what times is the total energy shared equally between the inductor and the capacitor?
$(e)$ If a resistor is inserted in the circuit,how much energy is eventually dissipated as heat?

The natural frequency of an $L-C$ circuit is $1,25,000 \text{ cycle/s}$. Then the capacitor $C$ is replaced by another capacitor with a dielectric medium of dielectric constant $K$. In this case,the frequency decreases by $25 \text{ kHz}$. The value of $K$ is