2024HSCShort answer

Q29 (a)

2 marks

Question

Two horizontal metal rods, A and B, of different materials are resting on a frictionless table. Initially they are at rest in position 1.
Both rods are then connected to a battery using wires. After the switch is turned on, currents of different magnitude flow in each rod. The rods move to position 2 after time, t. In position 2, B has a larger displacement than A from position 1. The masses of the wires are negligible.

Position 1 is reproduced below. Draw wires to show how the battery must be connected to the ends of the two rods in order for the magnitude of the current in each rod to be different, and for position 2 to be reached. No components, other than the wires, are required.

Uncropped source page 32 for question 29.a; requires human review and cropping — Reviewed visual · source page 32

Try the question before revealing the answer.

Solution

Criteria	Marks
Draws connections to both rods that show different currents flowing in opposite directions	2
Draws a complete circuit incorporating both rods	1

Sample answer:

Supplied marking guidance · human reviewed

Compare this with your working, not only your final sentence.

Syllabus alignment

Module 6 · Electromagnetism

The Motor EffectAnalyse the force between parallel current-carrying wires and its relation to the ampere and Newton's third law.

Spot a problem? Send feedback