1. You are provided with a measuring cylinder, two different tins labeled C and D, a thermometer, and other necessary materials.
2. Use the measuring cylinder provided to measure 100 cm of water and pour it into the tin label.
3. Heat the water in the tin almost to boiling (90°C).
4. Remove the tin and place it on a cork or wooden stand.
5. Insert the thermometer into the tin and record the temperature of the water every minute starting from 85°C until the temperature falls to 60°C.
6. Repeat the experiment with the tin labeled D using exactly the same volume of water and temperature range. Tabulate your readings.
7. On the same graph sheet and using the same axis and scales, plot two graphs of temperature on the vertical axis and time on the horizontal axis from the readings obtained using tins C and D.
8. Label the graphs appropriately as C and D to correspond with the tins used.
9. From each graph, read off the time taken to cool from 85°C to 65°C.
10. State two precautions taken to ensure accurate results. 

(b)i. Explain how heat losses by radiation and convection are minimized in a vacuum flask.

ii. State four factors that affect the rate of evaporation of a liquid in an open container.

1. Connect the circuit as shown in the diagram above. PQ is a potentiometer wire 100 cm long and R is a standard resistor of 5\(\Omega\).

2. With the jockey J not making contact with PQ, close the switch. Read and record the ammeter reading I. Open the switch.

3. Use the jockey to make contact with PQ at the 20cm mark such that PJ = I = 20 cm. Close the switch, read and record the value I\(_{i}\) of the ammeter. Evaluate I\(^{-1}\).

4. Repeat the procedure for other values of I = 35, 50, 65, and 80 cm. In each case, determine the corresponding values of I\(_{i}\), and I\(^{-1}\). Tabulate your readings.

1. Plot a graph of I\(^{i}\) on the vertical axis and I\(_{i}\), on the horizontal axis, starting both axes from the origin (0, 0).
2. From your graph deduce the value, of I\(_{o}\) of I\(_{i}\), when I\(^{-1}\)= 0.
3. Evaluate I\(_{o}\)e
4.  State two precautions taken to ensure accurate results. 

(b)) Define the e. m.f. of a battery

ii. A cell X e.m.f. 1.00 V is balanced by a length of 40.0 cm on a potentiometer wire. Another cell Y is balanced by a length of 60.0 cm on the same wire. Calculate the e.m.f. of Y.

You are provided with a uniform meter rule, a knife edge, masses and other necessary apparatus.

1. Suspend the metre rule horizontally on the knife edge. Read and record the point of balance G of the métre rule. Keep the knife edge at this point throughout the experiment.
2. Using the thread provided, suspend the object labelled W at the 15cm mark of the metre rule.
3. Suspend a mass M= 20g on the other side of G. Adjust the position of the mass until the metre rule balances horizontally again.
4. Read and record the position Y of the mass M on the metre rule.
5. Determine and record the distance L between the mass and G. Also determine and record the distance D between W and G.
6. Repeat the procedure for four other values of M = 30, 40, 50 and 60 g. In each casse ensure that W is kept Constant at the 15 cm mark and the knife edge at G.
7. Evaluate L\(^{-1}\) in each case. Tabulate your readings.
8. Plot a graph of M on the vertical axis against L\(^{-1}\) on the horizontal axis.
9. Determine the slope S, of the graph.
10. Evaluate \(\frac{4}{D}\)

State two precautions taken to obtain accurate results.
(b)i. State the principle of moments.

ii. Define centre of gravity

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

1. Fix a metre rule on the bench with its graduated side facing up.
2. Place the illuminated object at the 0cm end and the screen at the 100cm end of the rule such that the distance d between the illuminated object and screen is 100cm.
3. Record the distance d. Also, evaluate and record d\(^{2}\).
4. Place and move the Converging lens between the illuminated object and the Screen until a sharp diminished image of the object is formed on the screen.
5. Read and record the position Ih of the lens.
6. Now move the lens towards the object until another sharp image of the object is formed on the Screen.
7. Read and record the new position l\(_{2}\) of the lens.
8. Evaluate and record L= (l\(_{1}\) - I\(_{2}\)), also evaluate L\(^{2}\) and D = d\(^{2}\) - L\(^{2}\).
9. Repeat the procedure for four values of d= 85, 75, 65 and 55cm. Tabulate your readings.
10. Plot a graph or Don the vertical axis against d on the horizontal axis.
11. Determine the slope, s, of the graph.
12. Evaluate k = \(\frac{s}{4}\).
13. State two precautions taken to obtain accurate results.

(b)i. Explain the statement the focal length of a converging lens is 15cm.

ii. Distinguish between a real image and a virtual image.

You are provided with two resistance wires labeled A and B, a1\(\Omega\) standard resistor Rx, and other necessary apparatus.

1. Connect R\(_{x}\) in the left-hand gap of the metre bridge, a length L= 100cm of wire A in the right-hand gap, and the other apparatus as shown in the diagram above.
2. Determine and record the balance point P on the bridge wire NQ.
3. Measure and record l\(_{x}\) = NP and l\(_{y}\) = PQ.
4. Evaluate R\(_{1}\) = \(\frac{I_{y}}{L_{x}}\) = R\(_{x}\)
5. Repeat the procedure for four other values of L= 95, 85, 75 and 65cm. In each case, determine and record the balance point P and the length l\(_{x}\) and l\(_{y}\). Also, evaluate R\(_{1}\).
6. Repeat the experiment with the second wire B. Obtain the balance points P and the values of and l\(_{x}\) and l\(_{y}\).
7. Evaluate R\(_{1}\) = \(\frac{I_{y}}{L_{x}}\) = R\(_{x}\) in each case. Tabulate your readings.
8. Plot a graph of R\(_{2}\) on the vertical axis against R\(_{1}\) on the horizontal axis.
9. Determine the slope, s, of the graph.
10. Evaluate k = \(\sqrt s \).
11. State two precautions taken to obtain accurate results.

(b)i. State two advantages of using a potentiometer over a voltmeter for measuring the potential difference.

ii. Define the internal resistance of a cell.