Embibe Experts Solutions for Chapter: Electromagnetic Induction and Alternating Currents, Exercise 1: Level 1

An electric generator is based on_____

A primary coil is connected with an $AC$ source and a bulb is connected with the secondary coil. The voltage across the bulb is $6.0 \mathrm{V}$ and the current through the bulb is $0.4 \mathrm{A}$, The turns ratio is $5:1( \mathrm{Np}:\mathrm{Ns}=5:1)$. Calculate the current in the primary coil.

A transformer is used to glow a $140 \mathrm{W}-240 \mathrm{V}$ bulb at $240 \mathrm{V}$ AC. If current in the primary coil is $0.7 \mathrm{A}$, then the efficiency of the transformer is

How much current is drawn by the primary coil of a transformer, which steps down $220 \mathrm{V}$ to $55 \mathrm{V}$ to operate a device with an impedance of $275\mathrm{\Omega }?$

If the mains voltage is $230 \mathrm{V}$, then the peak voltage approximately is

For a given frequency, the inductive reactance of a coil at $100\mathrm{H}$ is $25\mathrm{\Omega }$. For the same frequency, the inductance reactance at $200\mathrm{H}$ will be

In an ac circuit, an inductor, a capacitor and a resistor are connected in series with $X_L=R=X_C.$ Impedance of this circuit is :

In the given circuit, what is the closest approximate frequency at which the ratio ${\mathrm{V}}_{\mathrm{out} }/{\mathrm{V}}_{\mathrm{in} }\text{is} 1/\sqrt{2}$ ?