NCERT Solutions for Chapter: Current Electricity, Exercise 2: ADDITIONAL EXERCISES

What conclusion can you draw from the following observations on a resistor made of alloy manganin?

A steady current flows in a metallic conductor of non-uniform cross-section. Which of these qualities is constant along the conductor: current, current density, electric field, drift speed?

Is Ohm’s law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm’s law.

A low voltage supply from which one needs high currents must have very low internal resistance. Why?

A high tension (HT) supply of, say, $6 \mathrm{kV}$ must have a very large internal resistance. Why?

Determine the equivalent resistance of networks shown below.

Determine the current drawn from a $12 \mathrm{V}$ supply with internal resistance $0.5 \mathrm{\Omega }$ by the infinite network shown below. Each resistor has $1 \mathrm{\Omega }$ resistance

The figure shows a $2.0 \mathrm{V}$ potentiometer used for the determination of internal resistance of a $1.5 \mathrm{V}$ cell. The balance point of the cell in open circuit is $76.3 \mathrm{c}\mathrm{m}$. When a resistor of $9.5 \mathrm{\Omega }$ is used in the external circuit of the cell, the balance point shifts to $64.8 \mathrm{c}\mathrm{m}$ length of the potentiometer wire. Determine the internal resistance of the cell.