AQA GCSE Physics Physics Paper 2 (Foundation), June 2023: Question 3

✅ Correct Answer

The arrows represent the direction (of the magnetic field).

💡 Key Knowledge

Magnetic field lines always point from the North pole to the South pole. For a straight current-carrying wire, circular field lines have an arrowhead showing the direction determined by the right-hand grip rule.

✅ Correct Answer

Tick: Increase the current in the wire

💡 Key Knowledge

The strength of the magnetic field produced by a current-carrying wire depends on the size of the current and the distance from the wire. A larger current creates a stronger magnetic field.

✅ Correct Answer

The third diagram down (showing parallel uniform field lines inside the solenoid, curving around the outside from North to South).

🧠 Exam Technique

Look for two key features in solenoid diagrams: field lines inside the coil must be straight, parallel, and closely spaced (strong uniform field), and field lines outside must loop around from one end to the other.

✅ Correct Answer

Sequence: D → A → B → C

💡 Key Knowledge

1. D: There is a current in the circuit (Switch closed).
2. A: A magnetic field is created around the electromagnet.
3. B: A resultant force acts on the iron arm, pulling it toward the electromagnet.
4. C: The iron arm returns to its original position (as contact breaks).

✅ Correct Answer

Tick: Decrease the distance between the electromagnet and the iron arm

❌ Common Errors

Students often incorrectly choose decreasing the number of cells or turns. Reducing cells or turns decreases the magnetic field strength, thereby reducing the force on the iron arm.

📐 Calculation Steps

1. Identify formula: period = 1 / frequency
2. Substitute values: period = 1 / 6.25
3. Calculate result: 0.16

Final Answer: 0.16 s

❌ Common Errors

Forgetting to include the unit ( s ) or incorrectly inverting the fraction (calculating frequency instead of period).

✅ Correct Answer

Tick: B

💡 Key Knowledge

In a longitudinal wave, a compression is a region where the particles are pushed close together (high pressure area). In Figure 9, region B shows the air particles bunched tightly together compared to A and C (which represent rarefactions where particles are spread apart).