(h) Plot a graph of V against I.

1. List the specific objectives for this topic. (0 mk)
2. Tabulate your results. (0 mk)
3. You are provided with a container labelled H and a blackened calorimeter. Nearly fill the blackened calorimeter with hot water whose initial temperature should be about 0oC and place this calorimeter on a wooden slab placed on a bench. (1 mk)
4. Set up the apparatus as shown in Figure 29. (0 mk)
5. Stir the hot water in the blackened calorimeter constantly and record the temperature fall θ of the water at one-minute interval. Continue recording the temperature θ until it has fallen to about 0oC. (2 mk)
6. List the apparatuses and materials that should be prepared for this topic. (0 mk)
7. Close the switch S. (0 mk)
8. Plot a graph of temperature, θ against time, t. (0 mk)
9. read carefully and understand the list of apparatuses and materials provided in each category; (1 mk)
10. arrange apparatuses and materials as prescribed in the 3 hours practical advance instructions; (1 mk)
11. Adjust the rheostat, Rh by sliding slowly from one end. (0 mk)
12. Use your graph to determine the melting point. (0 mk)
13. Pour the water from the calorimeter into the measuring cylinder and record its volume as V . (1 mk)
14. Cover the outer surface of the same calorimeter (after washing) with the metal foil provided by using rubber bands. Use the same volume V of hot water at about 0oC as in part (c) to fill the calorimeter covered with foil. Then, repeat the procedures outlined in part (b). Note that the initial temperatures should be the same for both cases. (3 mk)
15. Compare the temperature of the melting point of Naphthalene which was obtained from the graph with that obtained in part (d). (0 mk)
16. display the arranged list of apparatuses and materials on the bench according to the number of candidates registered in a particular examination; (1 mk)
17. Read and record the value of potential difference V across the conductor and current, I from the voltmeter and ammeter readings, respectively. (0 mk)
18. make sure that each candidate has apparatuses and materials as per 3 hours practical advance instructions; and (1 mk)
19. Repeat the experiment by changing the position of the slider of a rheostat for four other readings. (0 mk)
20. Using the same axes, draw the cooling curves for the blackened calorimeter with its content and calorimeter with a metal foil together with its content. (3 mk)
21. What is the relationship between the period of oscillation (T) and the mass (m) and spring constant (K) of an oscillating spring? (2 mk)
22. in case there is more than one examination session, teachers in charge/laboratory technicians ought to rearrange and replace (where necessary) the apparatuses and materials (where necessary) before the next session. (1 mk)
23. From each curve, estimate the time taken to cool from 0oC to 0oC. ith reasons, comment on your results. (5 mk)
24. Always adjust the rheostat until the ammeter pointer is exactly on the division of the meter scale before taking the reading. (0 mk)
25. State two important precautions to be observed during this experiment. (2 mk)
26. Quickly transfer the metal brass from hot water to the calorimeter with cold water and start the stopwatch. (0 mk)
27. Keep stirring until the mixture attains a steady temperature. Record this constant temperature as θf. (1 mk)
28. Assuming no heat is lost because of the surroundings, develop an equation which shows the heat exchange. (2 mk)
29. Using the equation developed in part (i), calculate the specific heat capacity, Cb of brass. (3 mk)
30. The refractive index of the material used in the prism can be shown as n = sin((A+Dm)/2) / sin(A/2), where D is the angle of minimum deviation and A is the angle of the prism. Determine the refractive index of the materials of the prism. (1 mk)
31. Determine the density, r of the liquid. (1 mk)
32. Compute the surface tension, g of the liquid from the equation, g = (p/6) * (1/r) * (8*pi*r) * (2/3) * (rho*g*S)/(1.9) (3 mk)

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(k) State the possible sources of errors in this experiment.

1. Calculate the slope of the graph. (3 mk)
2. Ratchet (1 mk)
3. Why is basic knowledge of first aid considered an essential life skill? (1 mk)
4. Frame (1 mk)
5. List any five most important first aid skills to be acquired by the teacher in charge/laboratory technician. (5 mk)
6. Explain the importance of Cardiopulmonary Resuscitation (CPR). (2 mk)
7. Anvil (1 mk)
8. Spindle (1 mk)
9. Sleeve/Barrel (1 mk)
10. Screw (1 mk)
11. Thimble/Circular scale (1 mk)

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(l) What are the precautions to be taken in performing this experiment?

1. Use the slope calculated in (h) and the equation, T=2π L/g, to calculate the acceleration due gravity, g. (4 mk)
2. State the formula for the moment of inertia of a rigid body about an axis of rotation. (1 mk)
3. What are laboratory technicians/teachers in charge responsible for? (1 mk)
4. Explain how to measure the periodic time. (2 mk)
5. make sure that the Zero mark of the thimble scale aligns with the datum line/central line of the main scale; (1 mk)
6. What should they ensure regarding laboratory operation? (1 mk)
7. List any five strategic roles of laboratory technicians/teachers in charge. (5 mk)
8. when turning the ratchet, the thimble should be moved without stacking. (1 mk)
9. List the different lengths of the pendulum to be used. (1 mk)
10. ensure the frame is held firmly. (1 mk)
11. What is the final step in calculating 'g'? (1 mk)
12. ensure proper alignment of the object to be measured. (1 mk)

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Sample Question 2: Determination of electromotive force (e.m.f.) and internal resistance of a cell.

1. If the distance between the point of suspension and G is denoted by l, and the period of oscillation is T, write down the relationship between T, l and the radius of gyration k. (2 mk)
2. Follow the procedures described in (a) to (h) to determine the coefficient of static friction. (10 mk)
3. Define static friction. (1 mk)
4. State the relationship between static and kinetic friction. (1 mk)

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(a) The arrangement of the equipment should be as shown in Figure 30: A I E K R Figure 30

1. Place masses on the scale pan until the wooden block starts moving, then record the reading on the spring balance as static friction, fs. (3 mk)
2. What is the purpose of plotting a graph of L against T²? (1 mk)
3. How is the slope of the graph related to the acceleration due to gravity? (2 mk)

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(b) With the tapping key closed, note and record the current reading I of the ammeter when R = 4 Ω.

1. Add 100 g mass on top the wooden block and then put some masses on the scale pan until block with 100 g starts to slide (move) and then record the reading on the spring balance as fs. (4 mk)
2. Explain the assumption related to small angles in simple harmonic motion. (1 mk)
3. What would happen if a large angle was used? (1 mk)

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(c) Repeat the procedure in part (b) for values of R equal to 6 Ω, 8 Ω, 12 Ω, 15 Ω, 20 Ω, and 25 Ω. Tabulate your results in a table as shown below: R (Ω) 4 6 8 12 15 20 25 I (A) 1/A (A-1) 48

1. Repeat part (g) for 200g 300 g, 400 g and 500 g. (3 mk)
2. What is the normal reaction force exerted by the surface on the block? (2 mk)
3. Calculate the coefficient of static friction. (2 mk)

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(d) Plot a graph of R against and determine its gradient. I

1. Which port should the red probe be connected to measure current? (1 mk)
2. Setting (1 mk)
3. Standardising (1 mk)
4. If the expected current is 150 mA, which port and range should be selected on the multimeter? (1 mk)
5. State one DO when using a voltmeter for measurement. (1 mk)

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(e) From your graph determine the e.m.f. of a cell.

1. State two 'Don'ts' when using a Vernier Calliper. (2 mk)
2. Close the jaws of the callipers and press zero. (1 mk)
3. List FOUR concerns of laboratory management. (4 mk)
4. Clean the measuring jaws properly before closing them. (1 mk)
5. Adjust the jib screws located under the movable jaw if they are loose. (1 mk)

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(f) Determine the value of R for which 1 =0. I

1. Never apply too much force on the jaws as it can easily shift the reading. (1 mk)
2. Explain the importance of 'Sustain' in the 5S method. (2 mk)
3. Do not place the object to be measured on the tips. (1 mk)
4. Do not use callipers with damaged measuring surfaces. (1 mk)

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(g) State the physical significance of the value of R obtained in part (f).

1. Test the ammeter to see if it allows current to pass through. (1 mk)
2. Identify THREE skills required for a person in charge of a laboratory. (3 mk)
3. Connect the ammeter in series with a resistor. (1 mk)
4. Make sure you have different values of resistors. (1 mk)
5. Start testing different ammeters by taking readings using the same resistor. (1 mk)

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Sample question 3: Determination of unknown resistance using the meter bridge circuit.

1. Check the proportionality of the source, resistor, and ammeter to protect the ammeter. (1 mk)
2. The role of calibration in laboratory management. (2 mk)
3. Do not use an exhausted source of e.m.f. (1 mk)
4. Why it is important to check for and reject fake laboratory apparatuses and materials. (2 mk)
5. Do not use a dry cell that is exhausted. (1 mk)
6. The normal laboratory fittings are working properly. (1 mk)

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(a) The arrangement of the equipment should be as shown in Figure 31. E Key R S G J L 100-L 1 1 A C B Figure 31

1. Test whether the voltmeter is conducting. (1 mk)
2. Explain the 'Shine' step. (2 mk)
3. Connect the Voltmeter across the dry cell. (1 mk)
4. Describe two methods mentioned to ensure the 'Sustain' step is effective. (2 mk)
5. Select the Voltmeter which gives the same reading. (1 mk)
6. Display the arranged list of apparatuses and materials on the bench according to the number of candidates registered in a particular examination. (1 mk)

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(b) Starting with R = 30 Ω, find the balance length AC=L along the metre bridge wire AB to the nearest centimetre.

1. The display. (1 mk)
2. The selection knob. (1 mk)
3. The ports. (1 mk)
4. Voltmeter (1 mk)

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(c) Repeat the procedure in part (b) for other values of R obtained by decreasing in steps of 5 Ω up to R = 5 Ω.

1. State its primary use. (1 mk)
2. Give an example of what it can measure. (1 mk)

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(d) Tabulate the values of R against L and include in your table the values of P= 1 . 1 100-L

1. Describe how the information should be handled. (1 mk)
2. Explain the process of understanding the list. (1 mk)
3. Detail the arrangement of apparatuses and materials. (1 mk)
4. Specify how the items should be displayed. (1 mk)

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(e) Plot a graph of P against R. 1

1. Explain the importance of managing choking. (2 mk)
2. Explain the importance of managing a suspected spinal/head injury. (2 mk)

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What does x represent?

1. Plot a graph of stretching force against extension. (0 mk)
2. Explain the function of the Thimble scale alignment with the datum line. (0 mk)
3. Explain the function of the ratchet when turning. (0 mk)
4. Determine the slope of the graph. (0 mk)
5. Explain the function of the frame. (0 mk)
6. Compute the average of the values of the last column of the table. (0 mk)
7. Explain the function of the anvil. (0 mk)
8. Compare the average value obtained in part (g) with the slope obtained in part (f). (0 mk)
9. Explain the function of the spindle. (0 mk)
10. Calculate the spring constant. (0 mk)
11. Explain the function of the sleeve/barrel. (0 mk)
12. Explain the function of the screw. (0 mk)
13. Explain the function of the thimble/circular scale. (0 mk)
14. Explain the function of the ratchet. (0 mk)
15. Explain the function of the locking device. (0 mk)

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(d) Plot a graph of R against 1/I and determine its gradient. (e) From your graph determine the e.m.f. of a cell. (f) Determine the value of R for which 1/I = 0. (g) State the physical significance of the value of R obtained in part (f).

1. Set up the apparatus as shown in Figure 28. (0 mk)
2. Mention two sources of errors and precautions taken in this experiment. (0 mk)
3. What is the physical meaning of the slope? (0 mk)
4. Plot a graph of R against 1/I and determine its gradient. (0 mk)
5. What apparatuses and materials are needed for this experiment besides normal laboratory fittings? (2 mk)
6. Describe the procedure from step (a) to (h). (5 mk)
7. State any three simple steps a teacher/laboratory technician needs to observe to develop safety consciousness. (3 mk)
8. Fill the burette with water to its brim. (0 mk)
9. the specifications given in the checklist should be adhered; (1 mk)
10. State the possible sources of errors in this experiment. (0 mk)
11. From your graph determine the e.m.f. of a cell. (0 mk)
12. the apparatuses, materials and equipment accommodate the number of candidates registered; (1 mk)
13. Explain the initial step when using electronic/digital Vernier Callipers to ensure proper zeroing. (0 mk)
14. What is the relation between angle i and angle r? (1 mk)
15. Determine the value of R for which 1/I = 0. (0 mk)
16. Hold a turning fork of a frequency, f=314 Hz horizontally near the burette at its upper end. Strike it with a rubber hummer. (0 mk)
17. What are the precautions to be taken in performing this experiment? (0 mk)
18. Informing students about hazards and risks before experiments. (1 mk)
19. the normal laboratory fittings are working properly; and (1 mk)
20. Identifying hazards in an experiment. (1 mk)
21. State the physical significance of the value of R obtained in part (f). (0 mk)
22. Open the tap to allow water to flow. Close the tap just when you hear the loudest sound (resonance at its fundamental mode) and record the length l (cm). (0 mk)
23. Repeat procedures (b) and (c) for f=384 Hz, 426 Hz, 480 Hz and 512 Hz tabulate your results including the column for f, and l. (0 mk)
24. Assessing risks by considering effects and chances of occurrence. (1 mk)
25. Choose six points (t, ) along the curve in part (g) and at each point draw the tangent to the curve and then determine the gradient, S to the curve at that point. Calculate and record the excess temperature θ-θr corresponding to each of the six points chosen. Hence, prepare a table that consists of values of S and values of θ-θr. (3 mk)
26. Determine the slope of your graph. (1 mk)
27. measuring instruments are calibrated. (1 mk)
28. Plot a graph of 1/f against l. (0 mk)
29. Using the results in part (h) draw a graph of the rate of cooling, S against “excess temperature” θ-θr. (2 mk)
30. State the law governing this experiment. (1 mk)
31. Controlling risks by implementing control measures. (1 mk)
32. What is the relation of angle i and angle r? (1 mk)
33. From the graph determine (i) the slope and (ii) the y-intercept. (0 mk)
34. State Newton‟s Law of Cooling. Compare the results in (i) with Newton‟s Law of Cooling and comment on the outcome. (3 mk)
35. Use the values calculated in (g) and the equation f = v / (4(l+e)) to determine the velocity, v of sound in air and the end correction, e. (0 mk)
36. What happens to static friction as the total mass on the wooden board increases? (0 mk)

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Sample question 3: Determination of unknown resistance using the meter bridge circuit. Apparatuses and Materials Apart from the common fittings in the laboratory, each teacher in charge/laboratory technician is recommended to have the following: A resistance box R capable of providing resistances of magnitude 5 Ω, 10 Ω, 15 Ω, 20 Ω, 25 Ω and 30 Ω, one size D dry cell labelled E, switch labelled K, a metre bridge, a standard resistor S of unknown resistance, a Galvanometer G, a jockey J and some connecting wires. Procedures (a) The arrangement of the equipment should be as shown in Figure 31. E Key R S G J L 100-L 1 1 A C B Figure 31 (b) Starting with R = 30 Ω, find the balance length AC=L along the metre bridge wire AB to the nearest centimetre. (c) Repeat the procedure in part (b) for other values of R obtained by decreasing in steps of 5 Ω up to R = 5 Ω. (d) Tabulate the values of R against L and include in your table the values of P = 1/(100-L). (e) Plot a graph of P against R. (f) Evaluate (i) the slope M of the best line (ii) the reciprocal N of M where N = 1/M. (g) Write the formula of the balanced bridge, hence discuss the physical meaning of N. (h) Identify any two sources of errors in this experiment. (i) Give two precautions that must be taken in performing this experiment?

1. Apart from the normal laboratory fittings, teachers in charge/laboratory technicians should prepare the following apparatuses and materials for each set of the experiment: G-clamp, wooden metre rule, standard mass of 100 g, and stopwatch. (0 mk)
2. Tabulate your results including the column for L, t, T and T2. (2 mk)
3. Put 20 g of Naphthalene in a test-tube. (1 mk)
4. The arrangement of the equipment should be as shown in Figure 31. (0 mk)
5. Starting with R = 30 Ω, find the balance length AC=L along the metre bridge wire AB to the nearest centimetre. (0 mk)
6. Hang the test-tube vertically using a retort stand. (1 mk)
7. What may cause accidents during laboratory practices? (1 mk)
8. What serves as a moral charter when performing laboratory experiments? (2 mk)
9. Fill the beaker with water and place it on the tripod stand and heat the water. Allow the temperature of water to reach about 40°C. (1 mk)
10. Repeat the procedure in part (b) for other values of R obtained by decreasing in steps of 5 Ω up to R = 5 Ω. (0 mk)
11. Tabulate the values of R against L and include in your table the values of P = 1/(100-L). (0 mk)
12. Place the test-tube containing naphthalene into the hot water in the beaker. Ensure that the naphthalene is completely immersed in water. Insert the thermometer into the naphthalene without touching the sides or bottom of the test-tube. Record the initial temperature of naphthalene. (1 mk)
13. Plot a graph of P against R. (0 mk)
14. Record the temperature of naphthalene at intervals of 1 minute until it has completely melted and the temperature starts to rise. Plot a graph of temperature against time. (1 mk)
15. Write the formula for Young's modulus in terms of force (F), area (A), extension (dl) and original length (l). (0 mk)
16. Tabulate the values of temperature,  and the corresponding values of time, t (in minutes) starting at t = 0). Also measure and record the room temperature, θ . r (0 mk)
17. Evaluate the slope M of the best line. (0 mk)
18. Evaluate the reciprocal N of M where N = 1/M. (0 mk)
19. Write the formula of the balanced bridge, hence discuss the physical meaning of N. (0 mk)
20. Identify any two sources of errors in this experiment. (0 mk)
21. State Newton‟s Law of Cooling. Compare the results in (i) with Newton‟s Law of Cooling and comment on the outcome. (7 mk)
22. Give two precautions that must be taken in performing this experiment? (0 mk)

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Sample question 4: Determination of unknown resistance, R and resistivity  using the meter bridge circuit. Apparatuses and Materials Apart from the common fittings in the laboratory, teachers in charge/laboratory technicians need to have the following: One size D dry cell labelled E, switch labelled K, a metre bridge, a standard resistor R of unknown resistance (R = 1 Ω, to be covered), a galvanometer G, a jockey J, crocodile clip, constantine wire (SWG 28) labelled W of length 150 cm, and some connecting wires. Procedures (a) Connect the resistor R and the wire W in series. Connect the free end of R to the left terminal of the right-hand gap of the metre bridge. Next, connect the wire W with the crocodile clip C to the other terminal of the right-hand gap. (b) Connect 5 Ω resistor in the left-hand gap and hence complete the Wheatstone bridge circuit in the usual manner. (c) Draw a circuit diagram of the set up outlined in (a) and (b). (d) Measure the length X of the wire W equal to 20 cm and clip the crocodile clip C at the end of this length. Find the balance length l as measured from the end with 5 Ω resistor. Calculate the equivalent resistance R in the right-hand gap. Increase X by 20cm each time and obtain corresponding values of X and R e Tabulate your readings (a total of 6 readings are required). (e) Measure the diameter of the wire W. (f) Plot a graph of R e against X. (g) Using your graph, deduce (i) the value of unknown resistance R (ii) the resistance per unit length of the wire W. (h) Find the resistivity of the material of the wire W. (i) State any two sources of error and precautions taken in this experiment.

1. Plot a graph of L against T2. (3 mk)
2. Connect the resistor R and the wire W in series. Connect the free end of R to the left terminal of the right-hand gap of the metre bridge. Next, connect the wire W with the crocodile clip C to the other terminal of the right-hand gap. (0 mk)
3. What should school laboratory staff be aware of to prevent accidents? (3 mk)
4. Connect 5 Ω resistor in the left-hand gap and hence complete the Wheatstone bridge circuit in the usual manner. (0 mk)
5. Draw a circuit diagram of the set up outlined in (a) and (b). (0 mk)
6. Measure the length X of the wire W equal to 20 cm and clip the crocodile clip C at the end of this length. Find the balance length l as measured from the end with 5 Ω resistor. Calculate the equivalent resistance Re in the right-hand gap. Increase X by 20cm each time and obtain corresponding values of X and Re. Tabulate your readings (a total of 6 readings are required). (0 mk)
7. Measure the diameter of the wire W. (0 mk)
8. Plot a graph of Re against X. (0 mk)
9. Plot a graph of r2 against v and determine its slope. (0 mk)
10. Using your graph, deduce the value of unknown resistance R. (0 mk)
11. Using your graph, deduce the resistance per unit length of the wire W. (0 mk)
12. Find the resistivity of the material of the wire W. (0 mk)
13. State any two sources of error and precautions taken in this experiment. (0 mk)

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