# "Explain" questions — OCR GCSE Physics A: Gateway Science (J249)

> 92 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. [Explain why gamma radiation is more hazardous to living cells than alpha radiation when a radioactive source is located …](https://www.gradenine.co.uk/q/explain-why-gamma-radiation-is-more-04410592)
2. [A student connects a battery, a lamp, and a switch in a series circuit. The student then adds a second identical lamp in…](https://www.gradenine.co.uk/q/a-student-connects-a-battery-a-05292994)
3. [Explain how red-shift and cosmic microwave background radiation (CMBR) each provide evidence for the Big Bang Theory.](https://www.gradenine.co.uk/q/explain-how-red-shift-and-cosmic-microwave-0c4a0640)
4. [A homeowner installs cavity wall insulation in their house. Explain how cavity wall insulation reduces the rate at which…](https://www.gradenine.co.uk/q/a-homeowner-installs-cavity-wall-insulation-0e47f162)
5. [A chocolate manufacturer heats solid chocolate in a large vat until it melts completely. Once all the chocolate has melt…](https://www.gradenine.co.uk/q/a-chocolate-manufacturer-heats-solid-chocolate-0fbf367f)
6. [A ice skater glides across a smooth ice rink at a constant velocity. She then pushes off a barrier at the edge of the ri…](https://www.gradenine.co.uk/q/a-ice-skater-glides-across-a-11be6045)
7. [A student heats a block of ice at 0 °C until it completely melts into water at 0 °C.

Explain, using the particle model,…](https://www.gradenine.co.uk/q/a-student-heats-a-block-of-135a2818)
8. [A skydiver jumps from an aircraft and falls towards the ground. Initially, the skydiver accelerates rapidly. After some …](https://www.gradenine.co.uk/q/a-skydiver-jumps-from-an-aircraft-14b6ce28)

## Related

- [OCR GCSE Physics A: Gateway Science (J249) revision notes](https://www.gradenine.co.uk/learn/ocr-gcse-physics-a-gateway-science-j249)
- [OCR GCSE Physics A: Gateway Science (J249) past papers](https://www.gradenine.co.uk/past-papers/ocr-gcse-physics-a-gateway-science-j249)
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