(i) Tabulate the results for both half and three quarter full including time and temperature for each case. (ii) Plot the cooling curves for both half and three quarter full in the same frame of axes. (iii) Use the two curves to obtain the ratio (1/2 full) : (3/4 full) of the times taken for both to cool from 85°C to 60°C. (iv) What conclusion can you draw on the ratio obtained in 2 (iii)? (v) Using your graph, comment how a quantity of a body/substance affects its rate of cooling?

1. Tabulate the results for both half and three quarter full including time and temperature for each case. (3 alama)
2. Plot the cooling curves for both half and three quarter full in the same frame of axes. (4 alama)
3. Use the two curves to obtain the ratio (1/2 full) : (3/4 full) of the times taken for both to cool from 85°C to 60°C. (3 alama)
4. What conclusion can you draw on the ratio obtained in 2 (iii)? (2 alama)
5. Using your graph, comment how a quantity of a body/substance affects its rate of cooling? (3 alama)

Boresha ili kuona majibu ya mfano.

You were assigned to install electricity to a new secondary school building. The district electric department provided you with two standard resistors labeled R1 and R2 each having 1 Ω, four standard resistors (2 Ω, 3 Ω, 4 Ω and 5 Ω), switch (K), voltmeter (V), ammeter (A) and connecting wires. Design a circuit having two loads labeled R1 and R2 connected in such a way that, the voltage drop across the two loads is the same. Following the procedures provided, perform an experiment and then answer the questions that follow. Procedures: (a) Complete a design by connecting a switch and two dry cells provided. (b) Close the switch, K and quickly record the reading on the ammeter and voltmeter. (c) Replace R2 with R2 = 0 Ω and quickly record the reading on the ammeter and voltmeter. (d) Repeat procedure 3(c) for R2 = 2 Ω, 3 Ω, 4Ω and 5 Ω.

1. Tabulate your results as shown in the following table: R (Ω) 0 1 2 3 4 5 P.d (V) I (A) (5 alama)
2. Complete a design by connecting a switch and two dry cells provided. (0 alama)
3. Draw a well labeled diagram for the experimental set-up. (5 alama)
4. Close the switch, K and quickly record the reading on the ammeter and voltmeter. (0 alama)
5. Replace R with R = 0 Ω and quickly record simultaneously the reading on the ammeter and voltmeter. (0 alama)
6. Evaluate the validity of the Ohm’s law in this experiment. (5 alama)
7. Deduce mathematical relation that can be used to evaluate the equivalent resistance (Req) when Ro = 10 Ω. (5 alama)
8. Repeat procedure 3(c) for R = 2 Ω, 3 Ω, 4Ω and 5 Ω. (0 alama)
9. Plot a graph of P.d (V) against I (A) and then comment on the numerical values of slope and intercept. (5 alama)

Boresha ili kuona majibu ya mfano.

(iii) Find the intercept of your graph. (iv) Determine the slope S of your graph. What does it imply? (v) What is the value of gravitational pull at your center? (vi) Suppose the amplitude of vibration diminishes due to increased air resistance, will the periodic time for 20 complete oscillations be different? Briefly explain.

1. Tabulate the results including the corresponding values of periodic time. (3 alama)
2. Find the intercept of your graph. (0 alama)
3. Determine the slope S of your graph. What does it imply? (0 alama)
4. Plot a graph of h (m) against T² (sec²). (3 alama)
5. What is the value of gravitational pull at your center? (0 alama)
6. Suppose the amplitude of vibration diminishes due to increased air resistance, will the periodic time for 20 complete oscillations be different? Briefly explain. (0 alama)

Boresha ili kuona majibu ya mfano.