# "Explain" questions — AQA A-Level Physics (7408)

> 148 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 scientist is investigating the emission of light from excited hydrogen gas. The gas emits light only at specific frequ…](https://www.gradenine.co.uk/q/a-scientist-is-investigating-the-emission-00ce6f46)
2. [Explain why ultrasound can be used to distinguish between two different soft tissues that are next to each other inside …](https://www.gradenine.co.uk/q/explain-why-ultrasound-can-be-used-03726318)
3. [A student wants to estimate the kinetic energy of a cyclist travelling along a flat road. Explain how the student could …](https://www.gradenine.co.uk/q/a-student-wants-to-estimate-the-04cbd911)
4. [Explain what happens to the molecules and the internal energy of a fixed mass of gas when it is compressed at constant t…](https://www.gradenine.co.uk/q/explain-what-happens-to-the-molecules-0c9f5528)
5. [A student builds a series circuit containing a battery, a diode and a fixed resistor. The student then reverses the conn…](https://www.gradenine.co.uk/q/a-student-builds-a-series-circuit-0dcde717)
6. [A student is investigating the properties of a superconducting material. The student records the following measurements:…](https://www.gradenine.co.uk/q/a-student-is-investigating-the-properties-0e7af0d4)
7. [A student measures the voltage across a battery using a voltmeter. He takes five readings: 9.1 V, 9.0 V, 8.6 V, 9.1 V, 9…](https://www.gradenine.co.uk/q/a-student-measures-the-voltage-across-0e93cf0e)
8. [A student measures the width of a human hair as 0.00008 m. Explain how the student could express this measurement using …](https://www.gradenine.co.uk/q/a-student-measures-the-width-of-1020c8ca)

## Related

- [AQA A-Level Physics (7408) revision notes](https://www.gradenine.co.uk/learn/aqa-a-level-physics-7408)
- [AQA A-Level Physics (7408) past papers](https://www.gradenine.co.uk/past-papers/aqa-a-level-physics-7408)
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