The cost of electricity

Question 1

what is an electrical appliance?

Answer 1

anything that needs electricity to work

Question 2

what are the 3 units energy can be measured in?

Answer 2

joules (J), kilojoules (kJ) or kilowatt - hours (kWh)

Question 3

what does power tell us?

Answer 3

how fast something transfers energy.

Question 4

What 2 units can power be measured as?

Answer 4

watts (W) or kilowatts (kW)

Question 5

what is 1 kW in W

Answer 5

1000

Question 6

how do you measure the amount of energy transferred?

Answer 6

By the amount of time

Question 7

What is the equation for calculating energy transferred?

Answer 7

Energy transferred (j) = power (W) x Time (s)

Question 8

calculate the energy transferred for when a 2000 watt kettle boils in 150 seconds

Answer 8

Energy transferred (j) = power (W) x Time (s)
Energy transferred = 2000 x 150
= 300 000 J

Question 9

what is the equation for when you want to calculate the energy transferred when you have kilowatts and time in hours?

Answer 9

Energy transferred (kWh) = power (kW) x Time (h)

Question 10

Calculate the energy transferred when you have a 3 kilowatt heater for 4 hours.

Answer 10

Energy transferred (kWh) = power (kW) x Time (h)
Energy transferred = 3 x 4
= 12 kWh

Question 11

How can you record how much electricity is used?

Answer 11

by electricity meters

Question 12

What unit do electricity record the amount of energy transferred?

Answer 12

in kWh

Question 13

during a 24- hour period does this person use more electricity during the day or night?
6PM = 44281.25 kWh
6AM = 44284.76 kWh
6PM = 44296.12 kWh
explain your answer

Answer 13

During the day.
Because:
Energy used during the night (6PM - 6AM) = 44284.76 - 44281.25 = 3.51 kWh
Energy used during the day (6AM - 6PM) =44296.12 - 44284.76 = 11.36 kWh

Question 14

Give the formula for how you can calculate your electricity bill

Answer 14

cost = Energy transferred (kWh) x price per kWh
OR
Cost = kWh x price per kWh