Energy Transfers (2)

Question 1

An electric motor is designed to transform electrical energy into __________ energy

Answer 1

kinetic

Question 2

Some of the electrical energy supplied to the motor is wasted as _________ energy and ________ energy

Answer 2

thermal / sound

Question 3

What happens to the energy wasted by the electrical motor?

Answer 3

Transferred to the surroundings

Question 4

Reducing the amount of energy is used by washing machines could reduce the amount of carbon dioxide emitted into the atmosphere.
Explain why

Answer 4

Less electricity needed and so few power stations needed

Question 5

Which of the appliances are designed to transform electrical energy to kinetic energy?

Answer 5

Food processor and hairdryer

Question 6

Which of the appliances waste energy as heat?

Answer 6

TV, table lamp and food processor

Question 7

Leaving the radiant heater switched on is likely to lead to more carbon dioxide being emitted into atmosphere than leaving the table lamp on for the same length of time.
Explain why

Answer 7

Transfers more energy and more electricity needs to be generated

Question 8

Suggest how data collected and displayed by the electronic device could be useful to the homeowner.

Answer 8

Can look for trends and can help reduce energy consumption as well as help reduce bills

Question 9

Electricity companies encourage people to use electricity between midnight and 7 am by selling the electricity at a lower cost.
Suggest why.

Answer 9

Supply exceeding demand

Question 10

The cermamic bricks are surrounded by ‘super efficient’ insulation

Answer 10

Reduce rate of energy transfer from ceramic bricks so keeping the ceramic bricks hot for longer

Question 11

Energy is transferred through the metal casing by __________
The warm air rising from the heater transfers energy to the room by __________

Answer 11

• conduction
• convection

Question 12

Give one advantage and one disadvantage of using nuclear power stations rather than gas - fired power stations to generate electricity

Answer 12

Advantage - produces no greenhouse gases
- produces long - term radioactive waste

Question 13

Why, on average, do wind turbines operate at maximum power output for only 30% of the time?

Answer 13

Wind is unreliable

Question 14

Give one advantage of using underground power cables rather than overhead power cables

Answer 14

Cannot be seen

Question 15

Describe how electricity is generated in a hydroelectric power station

Answer 15

Water moves from a higher level to a lower level transferring GPE to KE rotating a turbine to a generator transferring KE to electrical energy

Question 16

It is better for the environment if people switch off their televisions, instead of leaving them in ‘stand by’ mode

Answer 16

Tvs in stand by use electricity and generating electricity from fossil fuels produces CO2 which contributes to global warming