# "Explain" questions — OCR A-Level Physics A (H556)

> 86 questions · physics

## How to answer

WHAT + WHY. Every point paired with a because. Structure: X happens because Y. This causes Z because … Assessment Objective: AO2. Every "explain" answer on this spec is marked against exactly this pattern.

## Sample questions

1. [A lorry travelling at high speed along a motorway collides with a stationary car. After the collision, both vehicles mov…](https://www.gradenine.co.uk/q/a-lorry-travelling-at-high-speed-01c414ac)
2. [A fishing vessel uses sonar to locate a shoal of fish beneath it. Ultrasound pulses are emitted downward from the hull o…](https://www.gradenine.co.uk/q/a-fishing-vessel-uses-sonar-to-02846415)
3. [A engineer is designing a circuit for a new electric vehicle charging station. One charging port uses a motor with a hig…](https://www.gradenine.co.uk/q/a-engineer-is-designing-a-circuit-049ba73b)
4. [A street lighting system uses light dependent resistors (LDRs) to automatically switch lights on at night and off during…](https://www.gradenine.co.uk/q/a-street-lighting-system-uses-light-09c7785c)
5. [A hospital uses ultrasound waves to produce images of structures inside a patient's body. Explain how ultrasound waves a…](https://www.gradenine.co.uk/q/a-hospital-uses-ultrasound-waves-to-0a378766)
6. [A hospital uses a device that converts sound into electrical signals to monitor a patient's heartbeat sounds. Inside the…](https://www.gradenine.co.uk/q/a-hospital-uses-a-device-that-0d3ea4ed)
7. [A student is investigating how a spring stretches when different forces are applied to it. The student notices that at f…](https://www.gradenine.co.uk/q/a-student-is-investigating-how-a-101a8770)
8. [A thermistor and a fixed resistor are connected in series with a battery. Explain what happens to the total resistance o…](https://www.gradenine.co.uk/q/a-thermistor-and-a-fixed-resistor-124c9b9b)

## Related

- [OCR A-Level Physics A (H556) revision notes](https://www.gradenine.co.uk/learn/ocr-a-level-physics-a-h556)
- [OCR A-Level Physics A (H556) past papers](https://www.gradenine.co.uk/past-papers/ocr-a-level-physics-a-h556)
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