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Physics · Paper 2A · 2022

5 questions

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Questions (5)

Section A

1. 10 marks

Find the weight of the pendulum bob by using the following apparatuses: retort stand, clamps, metre rule, cotton thread, wood pads and stopwatch. Conduct an experiment through the given procedures and then answer the questions that follow. Procedures: (a) Set the experiment in such a way that the pendulum bob is at a height, (H) = 100 cm from the ground to the centre of the bob and a length, l of the thread be 60 cm from the point of suspension to the centre of the pendulum bob. (b) Slightly displace the pendulum bob at a small angle and release to allow it swing and measure the time t required to complete 20 oscillations and calculate its periodic time T. (c) Repeat the procedure in 1(b) by increasing the length of thread, l = 70 cm, 80 cm, 90 cm, 100 cm and 120 cm each time recording the values of H and t and hence its corresponding periodic time T. (d) Finally, measure the mass m in kg of the pendulum bob, by using a beam balance.

(i) Draw a labeled diagram of the experimental set up. 2 mk
(ii) Tabulate your results, including the values of t, l, H, T and T 2 . 2 mk
(iii) Plot the graph of H (cm) against T 2 ( sec 2 ). 2 mk
(iv) Determine the slope, S of your graph. 1 mk
(v) Determine the weight W of the metal ball in newton, given that 0.0254 1 W    mS  42K 1 mk
(vi) Show that T 2 intercept  g 1 mk
(vii) What is the physical meaning of K? 1 mk

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3. 0 marks

Conduct an experiment to verify whether wire Q has high conductivity or the same as that of copper. Follow the procedures provided and then answer the questions that follow. Procedures: (a) Connect a dry cell, an ammeter, a voltmeter, a key K and rheostat in series. (b) Join a voltmeter across the battery terminal. (c) With the Key K open, record the voltmeter reading. (d) With the Key K closed, adjust the rheostat so that the ammeter pointer is at exactly 0.2 A and record its corresponding voltmeter reading in volts. (e) Repeat procedure 3 (d) with ammeter readings of 0.4, 0.6, 0.8 and 1.0 A.

(i) Tabulate your results, including the values of I and V. 0 mk
(ii) Draw a well labeled diagram for the experimental set-up. 0 mk
(iii) Plot a graph of V and I. 0 mk
(iv) Use your graph to determine the internal resistance and e.m.f of that dry cell and comment on your answer comparing to the value given by the factory. 0 mk
(v) If the dry cell used in 3 (iv) is replaced by another dry cell an internal resistance that is twice that of the first one, what will be the magnitude of the current flowing in the circuit? 0 mk

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