ALTERNATIVE B

(a) You are provided with a variable DC power supply E, a key, an ammeter, a voltmeter and other necessary materials

(i) Set up a circuit as shown in the diagram above with E = 3.0V

(ii) Close the key.

(iii) Record the voltmeter reading, V

(iv) Read the corresponding ammeter reading, I

(v) Evaluate V\(^{-1}\) and I\(^{-1}\)

(vi) Repeat the procedure for the four other values of E = 4.5V, 6.0V, 7.5V and 9.0V.

(vii) Tabulate your readings.

(viii) Plot a graph with I\(^{-1}\) on the vertical axis and V\(^{-1}\) on the horizontal axis starting with both axes from the origin. (0, 0)

(ix) Determine the slope, s of the graph.

(x) Also, determine the intercept, c on the vertical axis

(xi) What does the slope, s represent?

(xii) State two precautions taken to ensure accurate results.

(b) State two methods by which an electric current can be produced

(i) State Ohm's law.