AQA GCSE PHYSICS · PAPER 2 · FOUNDATION & HIGHER
Exam Practice: Induced potential
Induced potential · Magnetism and electromagnetism · Lesson 6 of 8 · 14 marks · 15 minutes
|
Name |
|
Date |
|
Instructions
• Answer all the questions.
• Write your answers in the spaces provided.
• The marks for each question are shown in brackets - use this as a guide to how much to write.
• The answers are on separate pages at the back. Attempt every question before you look at them.
• Answer all questions. Use the mark allocation as a guide to how much to write.
Question 1 STATE (2 marks)
A magnet is pushed into a coil of wire connected to a voltmeter. State two ways of increasing the reading on the voltmeter.
|
|
|
|
|
|
(Total for Question 1 = 2 marks)
Question 2 EXPLAIN (3 marks)
A student holds a bar magnet still inside a coil of wire connected to a voltmeter. The voltmeter reads zero. Explain why and what they should do to get a reading.
|
|
|
|
|
|
|
|
(Total for Question 2 = 3 marks)
Question 3 DESCRIBE (3 marks)
Describe what happens to the reading on the voltmeter when the magnet is pulled out of the coil at the same speed as it was pushed in.
|
|
|
|
|
|
|
|
(Total for Question 3 = 3 marks)
Question 4 EXPLAIN (3 marks)
Explain why a current flows when a magnet is moved into a coil that is part of a complete circuit.
|
|
|
|
|
|
|
|
(Total for Question 4 = 3 marks)
Question 5 EXPLAIN (3 marks)
Explain why it is harder to push a magnet into a coil connected in a complete circuit than into a coil that is not connected.
|
|
|
|
|
|
|
|
(Total for Question 5 = 3 marks)
TOTAL FOR PAPER = 14 MARKS
|
|
Answers and mark scheme
Check your answer only once you have written one.
Question 1 (2 marks)
Move the magnet faster. Use a stronger magnet. Use more turns on the coil. (any two)
• One way 1 mark
• Another way 1 mark
Question 2 (3 marks)
There is no change in the magnetic field through the coil so no potential difference is induced. They should move the magnet in or out of the coil.
• No change in field 1 mark
• No p.d. induced 1 mark
• Move the magnet 1 mark
Question 3 (3 marks)
The voltmeter shows a reading of the same size but in the opposite direction (reversed polarity).
• A reading is shown 1 mark
• Same size 1 mark
• Opposite direction 1 mark
Question 4 (3 marks)
The movement of the magnet changes the field through the coil, which induces a potential difference. Because the circuit is complete, the p.d. makes a current flow.
• Changing field through the coil 1 mark
• p.d. induced 1 mark
• Complete circuit so current flows 1 mark
Question 5 (3 marks)
The induced current produces a magnetic field that opposes the change (the magnet's motion), so work must be done to push the magnet in. That work is transferred to electrical energy. With no complete circuit there is no current and so no opposing force.
• Induced current produces its own field 1 mark
• Opposes the motion 1 mark
• Work done is transferred to electrical energy 1 mark