Exam Questions

Question 0

What is meant by the term U-value? (2mark)

Answer 0

How good a material is at keeping energy in

Question 1

Plastic foam reduces energy transfer by convection. Explain why. (2marks)

Answer 1

• air bubbles are trapped in the foam

- so the air cannot circulate/move

Question 2

Explain the effect of replacing part of the outside wall with glass doors on the rate of energy transfer from the house (2marks)

U-value of the wall = 0.3
U-value of glass doors = 1.8

Answer 2

• The rate of energy transfer will increase

- Because the glass is not as good an insulator as the wall

Question 3

Why is a radiator painted black? (2marks)

Answer 3

• Matt black is a good emitter of infrared radiation

- so gives maximum rate of energy transfer

Question 4

The number of cooling fins affects the rate of energy transfer from the radiator. Explain how. (2marks)

Answer 4

• the fins increase the surface area

- so increasing the rate of energy transfer

Question 5

What 2 conclusions can be made about the relationship between the angle of incidence and the angle of refraction? (2marks)

Answer 5

• as the angle of i increases, so does the angle of r

- there is a positive correlation in a graph presenting this relationship

Question 6

How does he refraction of light passing from air into water compare to he refraction of light passing from air into plastic?(1mark)

Answer 6

Plastic refracts light more than water does

Question 7

An ethical implication about electricity generating (1mark)

Answer 7

Consequences for the future of decisions made now

Question 8

Which type of electromagnetic wave has the shortest wavelength?

Answer 8

Gamma

Question 9

One difference between U-V and visible light (1mark)

Answer 9

U-V has a shorted wavelength

Question 10

What does the observation of red-shift suggest is happening to the universe?(1mark)

Answer 10

It is expanding

Question 11

What is meant by ‘a reliable way of generating electricity’? (1mark)

Answer 11

Energy source is constant

Question 12

What does it mean to decommission a nuclear power station? (1mark)

Answer 12

Remove radioactive waste/materials/fuel

Question 13

Generating electricity can increase CO2 emissions.
The companies generating electricity could reduce CO2 emissions.
Give two ways the companies could so this.
(2marks)

Answer 13

• reduce use of fossil fuels

- use more renewable energy sources

Question 14

One kilogram of a gas has a much larger volume than one kilogram of a solid. Use kinetic theory to explain why. (4marks)

Answer 14

• strong forces of attraction
• holding particles in a fixed position
• but in a gas there are no forces between the particles
• so the particles fill the container