At very high frequencies, the current ( $i$ ) in the given circuit is

An alternating emf given by the equation $E=200 \sin (50 \pi t)$ (where, $E$ is in volts and $t$ is in seconds) is applied across a series combination of an inductor and a resistor having inductive reactance $40 \Omega$ and resistance $30 \Omega$ respectively. At time $t=1 \mathrm{~s}$, the power dissipated by the resistor is close to $\left(\cos 53^{\circ}=0.6\right)$

A series $L-C-R$ circuit is connected to an AC source of voltage $150 \sin (80 \pi t)$ volt. If the resistance of the resistor in the circuit is $25 \Omega$ and the impedance in the circuit is $75 \Omega$, the average power dissipated per cycle in the circuit is

In an ideal step up transformer, if the input voltage and input power are $V_1$ and $R_1$ respectively and the output voltage and output power are $V_2$ and $P_2$ respectively, then