A battery of e.m.f. $5.0 \mathrm{V}$ and internal resistance $2.0\Omega$ is connected to an $8.0\Omega$ resistor. Draw a circuit diagram and calculate the current in the circuit.

Calculate the current in each circuit in Figure 

(b) Calculate also the potential difference across the internal resistance for each cell, and the terminal p.d.

(i) 

(b) Calculate also the potential difference across the internal resistance for each cell, and the terminal p.d.

(ii)

The results of an experiment to determine the e.m.f. E and internal resistance r of a power supply are shown in Table. Plot a suitable graph and use it to find E and r.

A car battery has an e.m.f. of $12 \mathrm{V}$ and an internal resistance of $0.04\Omega$. The starter motor draws a current of $100 \mathrm{A}$.

Calculate the terminal p.d. of the battery when the starter motor is in operation.

Design a circuit using the thermistor in Figure that uses a cell of $10 \mathrm{V}$ and produces an output voltage of $5 \mathrm{V}$ at $50°\mathrm{C}$. Explain whether the voltage output of your circuit increases or decreases as the temperature rises.

Variation of resistance with temperature.

To make a potentiometer, a driver cell of e.m.f. $4.0 \mathrm{V}$ is connected across a $1.00 \mathrm{m}$ length of resistance wire.

(a) What is the potential difference across each $1 \mathrm{cm}$ length of the wire? What length of wire has a p.d. of $1.0 \mathrm{V}$ across it?