Junior Secondary · Science

Heat transfer: Practice Questions

5 multiple-choice questions marked as you go, and 5 written questions with worked solutions. All on Heat transfer.

10 questions22 marksFree, no account

Question 1

1 mark

Which of the following is the most important reason why air is a very poor thermal conductor?

Question 2

1 mark

How does the density of water change when it is heated from \(20^{\circ}\text{C}\) to \(60^{\circ}\text{C}\), and how does this lead to a convection current?

Question 3

1 mark

A refrigerator is designed to keep its contents cool. Which features of a refrigerator primarily reduce heat transfer from the surroundings to the inside?

Question 4

1 mark

When a student holds a short copper rod in a Bunsen flame, they quickly feel the heat. According to the particle theory, how is the thermal energy transferred through the rod?

Question 5

1 mark

Which of the following statements correctly explains why trapped air (such as in a wool sweater or fiberglass insulation) is such an effective thermal insulator?

Question 6

2 marks

Which mode of heat transfer allows thermal energy from the Sun to reach the Earth through the vacuum of space?

Write your answer out first, then check it against the worked solution.

Question 7

3 marks

In a room with a heater, explain why the heater is usually placed near the floor rather than near the ceiling to warm the entire room effectively.

Write your answer out first, then check it against the worked solution.

Question 8

3 marks

An experiment is conducted where identical wax discs are placed on two surfaces at room temperature: one silver and one styrofoam. The silver surface feels significantly colder, but the wax on it melts at a much higher rate. Explain this observation by discussing the conductive properties of the materials and the energy transfer involved.

Write your answer out first, then check it against the worked solution.

Question 9

4 marks

A vacuum flask (thermos) is an everyday object used to store hot or cold drinks.
(a)<\/b> The flask features a double-walled glass container with a vacuum in the space between the walls. Which two<\/b> modes of heat transfer are prevented by this vacuum? (1 point)
(b)<\/b> Explain, in terms of particles, why a vacuum is such an effective insulator against convection. (2 points)
(c)<\/b> Which mode of heat transfer can still travel across the vacuum space? (1 point)<\/p>

Write your answer out first, then check it against the worked solution.

Question 10

5 marks

A student uses a "convection box" to study the movement of air. The box is sealed with a glass front and has two chimneys, X and Y, on the top. A lit candle is placed inside the box directly under chimney X, and a piece of smouldering paper (which releases visible smoke) is held over the top of chimney Y.

a) Describe the path the smoke takes after it is released at chimney Y. (1 point)

b) Using the particle theory, explain why the air directly above the candle rises. (2 points)

c) Explain how the rising air at chimney X causes the smoke to move through the box from chimney Y. (2 points)

Write your answer out first, then check it against the worked solution.

* The content provided by thinka is generated by AI and may not always be accurate or up-to-date. Please use it as a supplementary resource and verify with official materials.

You've seen the model answer. Now get yours marked.

This page can show you how a good answer looks. It cannot tell you what your answer was missing. thinka marks your written work against the real mark scheme in about 15 seconds.

Get My Answers Marked Back to the notes

Want more questions like these? Get a fresh set on this topic, marked as you go.

Practise More