Electrical Power

How long (in seconds) will it take for a 60 W bulb to use 720 J of electrical energy? (2 s.f.)

Mathematical Equivalence

OFF

A bulb uses 45 000 J of energy in 300 seconds. What is its power rating (in W)? (2 s.f.)

Mathematical Equivalence

OFF

Calculate the power rating (in W) of an electric sewing machine which uses 4560 J of energy in 8 minutes. (2 s.f.)

Mathematical Equivalence

OFF

A 1200 W hairdryer is switched on for 20 minutes. How much electrical energy does it use (in J)? (3 s.f.)

Mathematical Equivalence

OFF

For how many minutes must a 600 W shaver be switched on in order to use 540 000 J of electrical energy? (2 s.f.)

Mathematical Equivalence

OFF

An electric fire uses 5.22 MJ of electrical energy in half an hour. Calculate the power rating of the fire (in kW). (2 s.f.)

Mathematical Equivalence

OFF

A car battery supplies a voltage of 12 V. One headlamp bulb draws a current of 3 A. What is the power rating of this bulb (in W)? (2 s.f.)

Mathematical Equivalence

OFF

An electric shower has a power rating of 12 W and draws a current of 0.11 A. What voltage (in V) is required to operate the shower? (3 s.f.)

Mathematical Equivalence

OFF

What current (in A) slows through a 230 V, 60 W household lamp when it is operating at the correct voltage? (2 s.f.)

Mathematical Equivalence

OFF

Calculate the power rating (in W) of an electric drill which draws a current of 3 A when connected to the mains. (2 s.f.)

Mathematical Equivalence

OFF