0625_s24_qp_61

1 A student investigates the stretching of a spring.

Fig. 1.1 shows the set-up. clamp stand metre ruler bench spring Fig. 1.1

(a) The student measures, and records in Table 1.1, the unstretched length l 0 of the spring. He does not include the loops at the ends of the spring in the measurement. The value l 0 is the length of the spring when the load L on the spring is 0.00 N.

Describe one technique you would use to obtain an accurate value for l 0. Draw a diagram to illustrate your answer [2]

(b) The student suspends a load L = 1.00 N from the spring. He records the new length l of the spring in Table 1.1.

He calculates the extension e of the spring using the equation e = (l – l 0) and records the value of e in Table 1.1.

The student repeats the procedure using loads L = 2.00 N, 3.00 N, 4.00 N and 5.00 N.

The readings and results are recorded in Table 1.1.

Calculate the extension e of the spring using the equation e = (l – l 0) when L = 5.00 N. Record this value of e in Table 1.1.

Table 1.1 L / N l / cm e / cm 0.00 2.1 0.0 1.00 6.0 3.9 2.00 10.6 8.5 3.00 14.9 12.8 4.00 19.3 17.2 5.00 23.7

[1]

(c) Plot a graph of L / N (y-axis) against e / cm (x-axis). Start both axes at the origin (0, 0).

Draw the best-fit line. 00

[4]

(d) Determine the gradient G of the graph. Show all your working and indicate on the graph the values you use.

G = [2]

(e) G is numerically equal to the spring constant k.

Record the value of k to a suitable number of significant figures for this experiment. Include the unit.

k = [2]

[Total: 11]

2 A student investigates the resistance of a wire.

Fig. 2.1 shows the circuit used. A V B C sliding contact S resistance wire d Fig. 2.1

(a) The student measures the current I in the circuit.

She places the sliding contact S at a distance d = 50.0 cm from B.

She measures the potential difference (p.d.) V50 across length d of the resistance wire.

Fig. 2.2 shows the ammeter and voltmeter.

(i) Record the readings on the ammeter and voltmeter. Include the units. V 6 7 9 8 10 4 5 2 1 3 0 A 0.6 0.8 1.0 0.4 0.2 0 Fig. 2.2

I = V50 = [2]

(ii) Calculate the resistance R50 of 50.0 cm of the resistance wire using the equation R50 = V50 I .

Include the unit.

R50 = [2]

(iii) Calculate r1, a value for the resistance per cm of the resistance wire, using the equation r1 = R50 d ,

where d = 50.0 cm. Include the unit.

r1 = [2]

(b) The student repeats the procedure in (a) using d = 75.0 cm and calculates r2 using the equation r2 = R75 d .

2.2

V75 = 6.1

R75 = 0.081

r2 = A student suggests that the resistance per cm of the resistance wire is constant.

(i) State whether your results support this suggestion and justify your statement by reference to the results. statement justification [2]

(ii) The student plans to plot a graph of resistance R against length d to test the suggestion.

Suggest suitable additional values of length d to use [2]

(c) A variable resistor is a circuit component that can be made using a coil of resistance wire.

Draw the electrical symbol for a variable resistor.

[1] [Total: 11]

3 A student investigates the image produced by a lens.

Fig. 3.1 shows the set-up. illuminated object lens screen x y bench Fig. 3.1 hO Fig. 3.2

(a) Fig. 3.2 shows the height hO of the illuminated object.

On Fig. 3.2, measure hO.

hO = [2]

(b) Fig. 3.1 is drawn to scale. The actual distance u between the illuminated object and the lens is 20.0 cm.

(i) On Fig. 3.1, measure the distance x.

x = [1]

(ii) Calculate the scale ratio r using the equation r = u x ,

where u = 20.0 cm.

r = [1]

(c) The student moves the screen until a focused image is formed on the screen.

(i) On Fig. 3.1, measure the distance y.

y = cm [1]

(ii) Calculate the actual distance v between the lens and the screen using the equation v = r y. Use your value for r from (b)(ii).

v = cm [1]

(d) Calculate the focal length f of the lens using the equation f = uv (u + v) .

Give your answer to a suitable number of significant figures for this type of experiment.

f = cm [2]

(e) In this type of experiment, it can be difficult to judge the screen position that produces the clearest image.

Suggest two precautions or techniques to overcome this difficulty. 1 2 [2]

(f) Fig. 3.2 shows the shape of the illuminated object. The image of the object is enlarged.

Draw a diagram to show the image that you would see on the screen.

[1]

[Total: 11]