TEST OF PRACTICAL KNOWLEDGE QUESTION You are provided with a voltmeter V, a chemical cell/ battery E; two standard resistors R, and R a potentiometer a key ...

TEST OF PRACTICAL KNOWLEDGE QUESTION

You are provided with a voltmeter V, a chemical cell/ battery E; two standard resistors R, and R a potentiometer a key K a jockey, and other necessary materials.

1. Set up a circuit as shown in the diagram above.
2. Close the key K.
3. Make contact with the potentiometer wire AB using the jockey at a point C such that AC = x = 20cm
4. Read and record the voltmeter reading
5. Evaluate x\(^{-1}\) and v\(^{-1}\) 
6. Repeat the procedure for other values of x= 30, 40, 50, 60 and 80cm. 
7. Tabulate your readings.
8. Plot a graph with V\(^{-1}\) on the vertical axis and x\(^{-1}\) on the horizontal axis, starting both axes from the origin (0, 0).
9. Determine the:
   (a) slope, s, of the graph;
   (b) intercept, c, on the vertical axis.
10. State two precautions taken to ensure accurate results.

(b)i. State the two devices in which ohm's law does not apply.

ii. A current of 1 A is supplied to two resistors of resistance 2\(\Omega\) and 3\(\Omega\) connected in parallel. Calculate the current in each resistor.