CAIE A Level 9702

Physics 2023 · Oct/Nov

11 Questions Q&A Available

Questions & Model Answers 11 Qs

Short Answer 1 mark

A student investigates the discharge of capacitors in the circuit shown in Fig. 2.1. The capacitors have capacitances C and C The student closes the switch to charge the capacitors. The switch is opened and a stop-watch is started. The capacitors discharge through the resistor of resistance R. At a fixed time t the voltmeter reading V is recorded. The experiment is repeated for different values of C and C For each combination of C and C , the combined capacitance C is calculated. It is suggested that C and V are related by the equation V = I where I is the initial current in the resistor.

Q2(a)

Short Answer 1 mark

A graph is plotted of lnV on the y-axis against on the x-axis. Determine expressions for the gradient and y-intercept. gradient = y-intercept =

Q2(b)

Short Answer 2 marks

Values of C, C and V are given in Table 2.1. Table 2.1 / 10 / 10 / 10 V / V ln (V / V) 2.2 2.2 2.45 ± 0.05 2.2 3.3 2.75 ± 0.05 2.2 5.6 3.05 ± 0.05 3.3 3.3 3.10 ± 0.05 3.3 5.6 3.50 ± 0.05 5.6 5.6 3.85 ± 0.05 The relationship between C, C and C+ C Calculate and record values of / 10 and ln (V / V) in Table 2.1. Include the absolute uncertainties in ln (V / V).

Q2(c)

Short Answer 2 marks

(i) Plot a graph of ln (V / V) against / 10 Include error bars for ln (V / V).

Q2(ii)

Short Answer 2 marks

Draw the straight line of best fit and a worst acceptable straight line on your graph. Label both lines.

Q2(iii)

Short Answer 1 mark

Determine the gradient of the line of best fit. Include the absolute uncertainty in your answer. gradient = [2] 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.850.900.951.001.051.101.151.201.251.301.351.40 In (V / V) / 10 To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series.

Q2(iv)

Short Answer 1 mark

Determine the y-intercept of the line of best fit. Do not include the absolute uncertainty. y-intercept =

Q2(d)(i)

Short Answer 1 mark

Using your answers to

Q2(d)(iv)

Short Answer 1 mark

, determine the values of R and I . Include appropriate units. Data: t = (30 ± 1) s R = =

Q2(ii)

Short Answer 1 mark

Determine the percentage uncertainty in R. percentage uncertainty in R = %

Q2(e)

Short Answer 1 mark

The experiment is repeated with the same value of t. Determine the combined capacitance C that gives a value of V of 1.20 V. C = F [1] [Total: 15]

Paper Details

Board	CAIE
Level	A Level
Subject	Physics
Code	`9702`
Year	2023
Session	Oct/Nov
Q&A	11 questions

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