Kumar Mittal Solutions for Exercise 1: QUESTIONS

A bulb and a capacitor are connected in series to a source of alternating current. What will happen on increasing the frequency of the current?

A choke coil and a bulb are connected in series to a $\mathrm{DC}$ source. If an iron core is inserted in the choke coil, is there any change in the brightness of the bulb?

An $\mathrm{AC}$ circuit has a power factor of $0.5$. What will be the phase difference between voltage and current in this circuit? Can you also tell whether the current leads the voltage or the voltage leads the current?

At resonance, what is the relation between impedance of a series $\mathrm{L}-\mathrm{C}-\mathrm{R}$ circuit and its resistance $\mathrm{R}$?

Variation of alternating current $\mathrm{I}$ with time $\mathrm{t}$ is shown in the graph below. Find the root mean square value of the current.  

 An $\mathrm{AC}$ source of $\mathrm{emf} \mathrm{e} = 200 \sin \mathrm{\omega t}$  is connected to a resistor of$50 \mathrm{\Omega }$, Calculate: Average current ($\mathrm{I}$av).

An $\mathrm{AC}$ source of $\mathrm{emf} \mathrm{e} = 200 \sin \mathrm{\omega t}$ is connected to a resistor of $50 \mathrm{\Omega }$. Calculate: Root mean square (rms) value of emf.

Why is the core of a transformer laminated?