For an $AC$ circuit $V = 15 \sin \omega t$ and $I = 20 \cos \omega t$,the average power consumed in this circuit is ..... $W$.

The potential differences across the resistance,capacitance,and inductance are $80 \, V$,$40 \, V$,and $100 \, V$ respectively in an $L-C-R$ circuit. The power factor of this circuit is:

$A$ coil of inductive reactance $31\,\Omega$ has a resistance of $8\,\Omega$. It is placed in series with a capacitor of capacitive reactance $25\,\Omega$. The combination is connected to an $A$.$C$. source of $110\,V$. The power factor of the circuit is:

$A$ sinusoidal alternating current of peak value $I_0$ passes through a heater of resistance $R$. What is the mean power output of the heater?

An inductor and a resistor of $25 \Omega$ are connected in series to an ac source of voltage $100 \sin (100 \pi t) \ V$. If the impedance of the circuit is $50 \Omega$,the average power dissipated per cycle in the circuit is: (in $W$)

The power factor of an $AC$ circuit containing peak current $2 \ A$ and peak voltage $1 \ V$ is $1/2$. The angle between voltage and current is: (in $^{\circ}$)