Questions

Question 0

What is the national grid? (1 mk)

Answer 0

A system of cables and transformers

Question 1

What effect does the waste energy from a power station have in the surroundings? (1 mk)

Answer 1

Warms it

Question 2

When a person uses the shower the mirror gets misty, why? (3 mks)

Answer 2

• water evaporates
• mirror surface is cooler than damp air
• causes condensation as particles move closer together (because cooler air cannot hold many water molecules)

Question 3

The homeowner installs an electrically heated mirror why does it not go misty when the person has a shower? (2mks)

Answer 3

• isn’t a big heat difference so the gas/steam does not condense
• rate of condensation is reduced

Question 4

What is a virtual image? (1 mk)

Answer 4

Rays of light seem to come from it but do not pass through it (formed where two virtual rays meet - rays not actually there)

Question 5

A vacuum flask is designed to reduce the rate of energy transfer by heating processes. Describe how the design of a vacuum flask keeps the liquid inside. (6 mks)

Answer 5

• silvered surfaces reflect rays
• silvered, shiny surfaces = poor emitters of infra-red radiation
• vacuum is all around hot liquid so stops rays escaping from everywhere
• plastic cap = poor conductor (stops convection currents at top of flask)
• glass container = poor conductor = reduces energy transfer by conduction

Question 6

Article foxes have small ears. How for share size of the ears help to keep the fox warm in a cold environment? (2 mks)

Answer 6

small surface area so reduces the energy transferred

Question 7

The main way the energy is transferred through the copper wall of the water tank is by the process of __________ (1 mk)

Answer 7

Conduction

Question 8

One effect that burning fossil fuels has on the environment (2 mks)

Answer 8

Non-renewable resources and release poisonous gases that kill wildlife and plants (contributing to global warming)

Question 9

One advantage if a pumped storage hydroelectric power station (1 mk)

Answer 9

Uses renewable resources = more environmental

Question 10

One example of infrared waves being used for communication (1 mk)

Answer 10

Remote controls

Question 11

Many scientists think that the ‘Big Bang’ theory describes the ________________________ (1 mk)

Answer 11

Origin of the universe

Question 12

The discovery of cosmic microwave background radiation was important because it…. (1 mk)

Answer 12

Provided more evidence to support the ‘Big Bang’ theory