How to Answer 'Suggest' Questions in IGCSE Physics

Use this guide to handle ‘Suggest’ questions confidently in Cambridge IGCSE Physics 0625 exams.

What makes ‘suggest’ different

Most command words ask you to recall or apply knowledge from the syllabus. ‘Suggest’ is different: it tells you that the answer requires you to go beyond direct recall and apply physics principles to a new situation.

There may be more than one correct answer. The examiner is looking for a plausible idea supported by sound physics reasoning.

A framework for ‘suggest’ answers

1. Identify the physics principle in the question. What topic area does this fall under?
2. State your suggestion clearly in one sentence.
3. Link it to the physics by explaining why your suggestion is plausible.

Worked examples

Example 1 (2 marks)

Question: A student measures the resistance of a filament lamp at different currents. The resistance increases as the current increases. Suggest why.

Strong answer: “As the current increases, the filament gets hotter. At higher temperatures, the metal ions vibrate more, so free electrons collide with them more frequently, increasing resistance.”

Why it scores: The suggestion (filament heats up) is linked to a physics mechanism (increased ion vibrations causing more frequent collisions).

Example 2 (2 marks)

Question: A spacecraft re-entering Earth’s atmosphere glows red. Suggest why.

Strong answer: “Friction with air molecules converts kinetic energy to thermal energy, heating the spacecraft surface to a high temperature. The surface then emits visible light (thermal radiation) because of its high temperature.”

Example 3 (1 mark)

Question: Suggest one reason why the student’s experimental value for g differs from 9.8 m/s^2.

Strong answer: “Friction in the apparatus or air resistance may have slowed the falling object, giving a lower measured value of g.”

Tips for ‘suggest’ questions

• Do not panic if the context is unfamiliar. That is deliberate.
• Name the physics principle you are using.
• If you cannot think of the ‘right’ answer, write any answer that is consistent with physics. Partial credit is common.
• Avoid vague phrases like “because of physics” or “due to energy”. Be specific.