You are provided with a potentiometer XY, a voltmeter, V, a standard resistor R, an accumulator, E a plug key, K, a jockey, and connecting wires.

1.  Connect a circuit as shown in the diagram above.
2. Close the key and use the jockey to make contact with the potentiometer with XY at a point N such that l = XN= 15cm.
3. Read and record the value of the potential difference V on the voltmeter.
4. Evaluate l\(^{-1}\) and V\(^{-1}\).
5. Repeat the procedure for five other values of I= 25, 35, 45, 55, and 65cm respectively. Read and record the value of V and evaluate V\(^{-1}\) and l\(^{-1}\) in each case. Tabulate your readings.
6. Plot a graph V\(^{-1}\) on the vertical axis against l\(^{-1}\)on the horizontal axis starting both axes from the origin (0,0).
7. Determine the slope, s, of the graph.
8. Evaluate k = \(\frac{1}{s}\)
9. State two precautions taken to ensure accurate re- results.

(b)i. State four factors on which the resistance of a wire depends.

ii. A resistance Wire of length 100cm is connected in a circuit. If the resistance per unit length of the wire is 0.02 \(\Omega\)cm\(^{-1}\), how much heat would be produced in the wire if a voltmeter connected across its ends indicates 1.5V while the current runs for 1 minute?