Using Energy

Question 1

What Does Our World Use A Lot Of?

Answer 1

The world we live in uses a lot of energy

Question 2

The energy supplied in household electricity is measured in ………..?

Answer 2

Kilowatt Hours

Question 3

How is Energy Transferred?

Answer 3

Energy is transferred from the power source to components in an electric circuit

Question 4

Energy transfer in electrical appliances is?

Answer 4

Always less than 100 per cent efficient

Question 5

What is a primary source of energy?

Answer 5

A naturally occuring source

Question 6

Which of the following is an example of a secondary source of energy?

Answer 6

Electricity is an example of a secondary source of energy.

Question 7

What major pollutant is produced when fossil fuels are burned?

Answer 7

Carbon dioxide

Question 8

What is energy measured in?

Answer 8

Energy is measured in joules

Question 9

A 230 V kettle has a current of 10 A. What is the power of the kettle?

Answer 9

2300 W

Question 10

How many joules of energy are transferred in 10 seconds by a 60 W lamp?

Answer 10

6 J

Question 11

A 2 kW electric heater is left running for 5 hours. How many kWh of energy are transferred?

Answer 11

10 kWh

Question 12

A 3 kW heater is left on for 2 hours. How much does this cost at 10p per kWh?

Answer 12

total cost = number of units x cost per unit.

Question 13

A low-energy electric lamp is marked “20 W” and gives out 10 W of light. How effecient is the lamp?

Answer 13

useful energy transferred / energy supplied x 100