MDCAT
Physics
2019
Physics · Current Electricity
Work through this past-paper style MCQ, then read the full explanation. Practice more physics questions on mMCQ with adaptive practice and topic analytics.
Question
Calculate the rate at which energy is transferred by a 220 V mains supply, which provides a current of 0.1 A to an LED?
Options
- A
2.2 W
- B
2.2 kW
- C
22 kW
- D
22 W
Explanation
Power = Voltage x Current; 220 x 0.1 = 22W
Power = Voltage x Current
Putting in the values gives us an incorrect answer.
Power = Voltage x Current
Putting in the values gives us an incorrect answer.
Power = Voltage x Current
Putting in the values gives us an incorrect answer.
A simple formula will be used here:
Power = Voltage x Current
220 x 0.1 = 22W
Tagged under Physics · Current Electricity · 2019