$A$ bulb is connected first with $DC$ and then $AC$ of the same voltage. In which case will it shine more brightly?

An $AC$ source of $20\,V$ (assuming standard frequency $f = 50\,Hz$ for calculation) is connected to an inductance of $100\,mH$,a capacitance of $100\,\mu F$,and a resistance of $120\,\Omega$ as shown in the figure. The time in which the resistance,having a thermal capacity of $2\,J/^{\circ}C$,will get heated by $16^{\circ}C$ is ..........$s$.

In the circuit shown, the charge $q$ varies with time $t$ as $q = t^2 - 5$, where $q$ is in coulomb and $t$ is in second. At time $t = 3$ second, the voltage $V_{AB}$ in volt will be:

Three alternating voltage sources $V_1 = 3 \sin \omega t \text{ V}$,$V_2 = 5 \sin(\omega t + \phi_1) \text{ V}$,and $V_3 = 5 \sin(\omega t - \phi_2) \text{ V}$ are connected in series with a resistor $R = \sqrt{\frac{7}{3}} \, \Omega$ as shown in the figure (where $\phi_1 = 30^\circ$ and $\phi_2 = 127^\circ$). Find the peak current (in Ampere) through the resistor.

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 $W$)

Find the peak current and resonant frequency of the following circuit (as shown in the figure).