CAIE Physics (9702)

In this experiment, you will determine the resistivity of a metal. 3 V d.c. E = V 3 V d.c. nail 22 Ω wooden strip metal wire Fig. 1.2 (not to scale) The distance between the nail and Q is x, as shown in Fig. 1.2. Adjust the position of Q until x is approximately 45 cm. Measure and record x and V. x = V =

Change x by adjusting the position of Q on the wire. Use six different values of x. For each value of x, measure V. Record your results in a table. Include values of in your table.

(i) Plot a graph of on the y-axis against x on the x-axis.

Draw the straight line of best fit.

Determine the gradient and y-intercept of this line. gradient = y-intercept =

It is suggested that the quantities V and x are related by the equation = Ax + B where A and B are constants. Using your answers in (c)(iii), determine the values of A and B. Give appropriate units. A = B =

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(i) Use a micrometer to measure the diameter d of the wire. d =

It is suggested that A is given by the equation A = - where R is 22 Ω and ρ is the resistivity of the metal. Using your answers in (a), (d) and (e)(i), determine a value for ρ. Give an appropriate unit. ρ = [2] [Total: 20] You may not need to use all of the materials provided.

In this experiment, you will investigate the extension of two springs. bench mass hanger springs boss stand clamp of the spring combination is measured from the top coil of the top spring to the bottom coil of the bottom spring, as shown in Fig. 2.1. Measure and record L =

Estimate the percentage uncertainty in your value of L . Show your working. percentage uncertainty = % [1] Measure and record L = k =- L where W is 0.981 N. Calculate k. k =

Justify the number of significant figures that you have given for your value of k. nuts. M = V = steel where the density ρ steel of steel is 7.8 g cm Calculate V. V = [2] air paper clip four nuts springsair Measure and record Lair air = bottom of the beaker, as shown in Fig. 2.3.oil beakeroil oil Measure and record Loil oil = air- Loil air- Loil ) =

Repeat

with the four larger steel nuts. M = V = air = oil = air- Loil ) =

It is suggested that the relationship between Lair, Loil and V isair- Loil ) = ZV where Z is a constant. Using your data, calculate two values of Z. first value of Z = second value of Z =

It is suggested that the percentage uncertainty in the values of Z is 5%. Using this uncertainty, explain whether your results support the relationship in (c).

The density ρoil of the oil is related to Z byZ =oil where g is 9.81 N kg Use your second value of Z to determine ρoil . Give an appropriate unit. oil =

(i) Describe four sources of uncertainty or limitations of the procedure for this experiment. For any uncertainties in measurement that you describe, you should state the quantity being measured and a reason for the uncertainty. 1 2 3 4

Describe four improvements that could be made to this experiment. You may suggest the use of other apparatus or different procedures. 1 2 3 4 [4] [Total: 20] Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. 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. Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge.