S L Arora Solutions for Chapter: Electromagnetic Induction, Exercise 2: VERY SHORT ANSWER CONCEPTUAL PROBLEMS

Two similar circular co-axial loops carry equal currents in the same direction. If the loops be brought nearer, what will happen to the currents in them?

Self-induction is called the inertia of electricity. Why?

A solenoid with an iron core and a bulb are connected to a d.c. source. How does the brightness of the bulb change when the iron core is removed from the solenoid?

A plot of magnetic flux $\left(\varphi \right)$ versus current $\left(I\right)$ is shown in FIg.6.50 for two inductors $A$ and $B$. Which of the two has larger value of self-inductance?

If the self-inductance of an air core inductor increases from $0.01 \mathrm{mH}$ to $10 \mathrm{mH}$ on introducing an iron core into it, what is the relative permeability of the core used?

Why is the induced emf in a coil zero when its plane is normal to the magnetic field even though maximum magnetic flux is linked with the coil in this position?

Why are resistance coils double wound?

A metallic piece gets hot when surrounded by a coil carrying high-frequency alternating current. Why?