(a) The potential difference applied across a given resistor is altered so
that the heat produced per second increases by a factor of 9. By what
factor does the applied potential difference change?
(b) In figure shown, an ammeter A and a resistor of 4 are connected
to the terminals of the source. The emf of the source is 12 V having
an internal resistance of 2. Calculate the voltmeter and ammeter
readings. (3 marks)