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?

Using the diagram above as a guide, carry out the following instructions.

1. Place the meter rule provided on the knife edge and adjust the position until it balances horizontally.
2. Read and record the balance point, G. Keep the knife edge at this point throughout the experiment.
3. Suspend a mass Q= 50.0g at a point P 30cm from the 0cm end of the rule.
4. On the other side of G, suspend the mass M =30g. Adjust its position until the rule settles down horizontally as shown in the diagram above.
5. Read and record the position R of M.
6. Record the distance, d, between G and R. Also read and record the distance, a, between P and G.
7.  Repeat the procedure for four other values of M = 40, 50, 60, and 70 with Q kept in the same position. Evaluate d\(^{-1}\) in each case. Tabulate your readings.
8. Plot a graph of M on the vertical axis against d\(^{-1}\) on the horizontal axis.
9. Determine the slope,s, of the graph.
10. Evaluate k = \(\frac{s}{Q}\)
11. State two precautions taken to ensure accurate results.

(b)i. Explain the moment of a force about a point

ii. State the conditions necessary for a body to be in equilibrium when acted upon by a number of parallel end forces

1. Determine and record the approximate focal length f\(_{o}\) of the concave mirror provided.
2. Arrange the ray box, the mirror, and the screen as shown in the diagram above.
3. Adjust the ray box to a distance b = 20.0cm from the mirror.
4. Adjust the position of the screen until a sharp image of the cross wire of the ray box is formed on it.
5. Measure and record the distance, a, of the screen from the mirror. Evaluate \(\frac{a}{a}\) =1.
6. Repeat the procedure for four other values of b = 25.0, 30.0, 35.0, and 40.0cm. Tabulate your readings.
7. Plot a graph of l on the vertical axis against a on the horizontal axis.
8. Determine the slope,.s, of the graph. Evaluate S\(^{-1}\).
9. State two precautions taken to ensure accurate results.

(b)i. An object is placed at a distance of 10cm in front of a concave mirror of focal length of 15cm. Determine the characteristics of the image formed.

ii. Briefly describe how you obtained f\(_{o}\) in (a)i) above.

1. Measure and record the emf, V\(_{o}\) of the cell provided.
2. Connect a circuit as shown in the diagram above.
3. With the key, K closed vary the rheostat, Rh to obtain a current 1 = 0.20A. Read and record the corresponding value of the potential difference, V on the voltmeter.
4. Evaluate 1\(^{-1}\) and V\(^{-1}\).
5. Repeat the procedure for four other values of l = 0.25, 0.30, 0.35 and 0.40 A. Tabulate your readings.
6. Plot a graph V\(^{-1}\) on the vertical axis against 1\(^{-1}\) on the horizontal axis.
7. Determine the slope, s, of the graph
8. Evaluate s\(^{-1}\).
9. State two precautions taken to ensure accurate results.

 (b)i. Explain Ohmic conductor:

ii. Explain resistivity of the material of a wire.

You are provided with a metre rule, a knife edge, two pieces of thread and two masses m\(_{1}\) and m\(_{2}\)

1. Record the values of m\(_{1}\) and m\(_{2}\).
2. Balance the metre rule horizontally on the knife edge and record the balance point G.
3. With the knife edge at the 60 cm mark of the metre rule, suspend m\(_{1}\) at the 20 cm mark and m\(_{2}\) at a suitable mark such that the rule balances horizontally as illustrated in the diagram above.
4. Record the positions Y of m\(_{1}\) and Q of m\(_{2}\). 
5. Evaluate 1= P - Y and d = Q - P
6. Repeat the procedure for four other positions of m, at 18, 16, 14 and 12 cm marks.
7. In each case, evaluate and record l and d.
8. Tabulate your readings.
9. Plot a graph of l on the vertical axis against d on the horizontal axis.
10. Determine the slope of the graph.
11. State two precautions taken to ensure accurate results.

(b}i. With the aid of a diagram, indicate the forces acting on the metre rule in the experimental set-up above.

ii. Define moment of a force about a point and state its S.1. unit.