A current of 0.25 A flows through a 47 Ω resistor.
.1
Calculate the power transferred in the resistor.
Give your answer to 2 significant figures.
[3 marks]
.2
The p.d. across the resistor is 11.75 V. In one minute, 15 C of charge flows through it.
Calculate the energy transferred in one minute.
[2 marks]
.3
Show that your answers to parts 1 and 2 agree, and explain why.
[2 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
An electric motor in a lift raises the lift through a height of 12 m in 20 s. The mass of the lift is 800 kg.
Gravitational field strength = 9.8 N/kg.
.1
Calculate the energy transferred to the lift's gravitational potential store.
[2 marks]
.2
Calculate the useful power output of the motor.
[2 marks]
.3
A second motor raises the same lift through the same height in 30 s.
Explain why the second motor has a lower power output.
[2 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student hangs weights on a spring and measures its length each time.
Spring results. Weight added in newtons and total length in centimetres: 0 N, 20.0 cm; 1.0 N, 22.5 cm; 2.0 N, 25.0 cm; 3.0 N, 28.5 cm; 4.0 N, 30.0 cm; 5.0 N, 32.5 cm.
Weight added (N)
Length of spring (cm)
0
20.0
1.0
22.5
2.0
25.0
3.0
28.5
4.0
30.0
5.0
32.5
.1
Calculate the extension of the spring when the weight is 4.0 N.
[1 mark]
.2
Identify the anomalous result. Give the weight.
[1 mark]
.3
Use the other results to calculate the spring constant in N/m.
[2 marks]
.4
Suggest one way the student could make the length readings more accurate.
[1 mark]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student wants to find the density of a small irregular stone. They have a balance, a measuring cylinder and water.
.1
Describe how the student can find the volume of the stone.
[2 marks]
.2
The water level rises from 50 cm³ to 70 cm³. The mass of the stone is 52 g.
Calculate the density of the stone.
[2 marks]
.3
Suggest one reason the student's value for the volume might be inaccurate.
[1 mark]
7 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student holds a steel paperclip near a bar magnet.
.1
Explain the difference between a permanent magnet and an induced magnet.
[2 marks]
.2
The paperclip is attracted to the north pole and also to the south pole of the magnet. Explain why.
[2 marks]
.3
Describe how the strength of the magnetic field changes as you move further from the magnet.
[1 mark]
.4
With no magnets nearby, a compass needle still points north. Explain what this shows about the Earth.
