Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Electromagnetism
68 practice questions
Topics covered
Practice questions
21–30 of 68
Question 21
1 mark · Easy
Answer and see the solution →What is the primary purpose of a generator?
Question 22
2 marks · Easy
Answer and see the solution →(a)[1 mark]A dynamo is attached to a bicycle wheel. Describe briefly what happens to the magnetic field inside the dynamo as the bicycle wheel turns.
(b)[1 mark]Explain how the turning magnet inside the dynamo leads to a current in the coil.
Question 23
2 marks · Easy
Answer and see the solution →Explain why no voltage is produced in a wire if it is held still in a magnetic field and why a voltage is produced when the wire is moved.
Question 24
1 mark · Easy
Answer and see the solution →Give one practical application of electromagnetic induction.
Question 25
4 marks · Normal
Answer and see the solution →A straight wire is moved quickly at right angles through the magnetic field between the poles of two magnets, as shown below.
A wire AB moving at right angles across a uniform magnetic field between north and south poles. (a)[1 mark]State the name of the process by which a voltage is produced in the wire.
(b)[2 marks]Explain how the movement of the wire causes a voltage to be induced in it.
(c)[1 mark]Give one way, other than moving the wire faster, to increase the size of the induced voltage.
Question 26
3 marks · Normal
Answer and see the solution →Generators are used in power stations to produce electricity for homes and businesses.
Explain, in terms of electromagnetic induction, how a generator can produce electricity. Include what needs to move and why this movement is necessary.
Question 27
1 mark · Normal
Answer and check →Which of the following will NOT increase the size of the voltage induced in a wire by electromagnetic induction?
- A.Using a stronger magnet
- B.Moving the wire faster across the magnetic field
- C.Increasing the number of turns in the coil
- D.Using a weaker magnet
Question 28
3 marks · Normal
Answer and see the solution →A student investigates how the induced voltage in a coil changes with the speed of a moving magnet. Her results are shown in the table.
Induced voltage vs. speed of magnet Speed of magnet (cm/s) Induced voltage (V) 2 0.6 4 1.2 6 1.8 8 2.4 (a)[1 mark]Describe the relationship between speed and induced voltage shown by the data.
(b)[2 marks]Predict the induced voltage if the speed of the magnet is increased to 10 cm/s.
Question 29
3 marks · Normal
Answer and see the solution →When a magnet is pushed into a coil of wire, a voltage is produced across the ends of the coil. The voltage disappears if the magnet stops moving.
(a)[2 marks]Explain why a voltage is only induced when the magnet is moving.
(b)[1 mark]Give one way to increase the maximum voltage produced in this experiment.
Question 30
4 marks · Normal
Answer and see the solution →A portable generator is used at a roadworks site to provide electrical power. The generator has a coil rotating inside a strong magnetic field.
Describe how electricity is produced in this generator and state two factors that will increase the amount of electricity generated.
(a)[2 marks]Describe what happens as the generator coil turns inside the magnetic field.
(b)[2 marks]State two ways the amount of electricity generated can be increased.