Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Units (Magnetism & Electromagnetism)
80 practice questions
Topics covered
Practice questions
31–39 of 39 · Normal
Question 31
4 marks · Normal
Answer and see the solution →A straight wire carries a current vertically upwards. Plotting compasses are placed in a horizontal plane around the wire.
(a)[2 marks]Describe the shape of the magnetic field around the wire.
(b)[2 marks]State and use the right-hand grip rule to find the direction of the field when looking from above.
Question 32
2 marks · Normal
Answer and see the solution →State two ways to increase the strength of the magnetic field produced by a current-carrying wire.
Question 33
3 marks · Normal
Answer and see the solution →Draw a labelled diagram to show a uniform magnetic field between two bar magnets. Indicate the direction of the field.
Question 34
2 marks · Normal
Answer and see the solution →Explain why a soft iron core is used in an electromagnet rather than a steel core.
Question 35
4 marks · Normal
Answer and see the solution →A student wants to make the field of an electromagnet stronger.
(a)[2 marks]Give two adjustments they can make to the coil, apart from increasing the current.
(b)[2 marks]Describe and explain how adding a core to the coil would help.
Question 36
1 mark · Normal
Answer and check →Which statement correctly describes the direction of the magnetic field around a straight current-carrying wire using the right-hand grip rule?
- A.The field circulates in the direction of the left-hand fingers around the wire.
- B.The field circulates in the direction of the right-hand fingers when the thumb points in the direction of the current.
- C.The field radiates away from the wire perpendicular to the current.
- D.The field circulates in the opposite direction to the right-hand grip rule.
Question 37
5 marks · Normal
Answer and see the solution →Two students set up the experiment shown.
Bar magnets with a gap between north and south poles, iron filings sprinkled in-between. (a)[2 marks]Draw the magnetic field pattern expected between the two poles. Clearly label the direction of the field.
(b)[3 marks]Explain why this arrangement produces a uniform magnetic field in the gap.
Question 38
4 marks · Normal
Answer and see the solution →A transformer has 300 turns on its primary coil and 1200 turns on its secondary coil. The voltage applied to the primary coil is 5.0 V a.c.
(a)[2 marks]Calculate the voltage across the secondary coil.
(b)[2 marks]If the transformer is 100% efficient and the current in the primary coil is 1.2 A, calculate the current in the secondary coil.
Question 39
5 marks · Normal
Answer and see the solution →Below is a table showing the currents and voltages measured for a simple circuit containing a solenoid. The power supplied is also included.
Current, Voltage, and Power for a Solenoid Circuit Current (A) Voltage (V) Power (W) 0.50 3.0 1.5 0.80 5.0 4.0 1.20 7.5 9.0 (a)[2 marks]State the unit for power, and explain how the power values are calculated using current and voltage.
(b)[3 marks]If you wanted to make the electromagnet in the solenoid stronger, explain two changes you could make to increase the power supplied to it.