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Electrical power and potential difference

The heating element of a 23V heater has a resistance of 4.0 when the heating element is connected to a 12V power supply,calculate:
I. The current through it
ii. The electrical power supplied to it
iii. The energy in joules, transferred to the heating element by an electric current in 20 minutes
Original post by Ibrahimbuhari
The heating element of a 23V heater has a resistance of 4.0 when the heating element is connected to a 12V power supply,calculate:
I. The current through it
ii. The electrical power supplied to it
iii. The energy in joules, transferred to the heating element by an electric current in 20 minutes


This is about understanding the relationship and differences between voltage current power and energy and their SI unit definitions.

You will need ohms law V = IR and power W = VI

Also remember power W = joules per second.
(edited 2 years ago)

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