Home › UCE (O-Level) › Physics › Electric circuits › A current of 4 amperes passes through a heater w…
A current of 4 amperes passes through a heater while the voltage across it is 12 volts. What power does the heater dissipate?
A48 watts
B16 watts
C3 watts
D24 watts
Answer & Solution
Correct answer: A. 48 watts
1. Electrical power is the rate at which electrical energy is converted in a circuit.
2. Power is exactly equal to current multiplied by voltage, with no extra constant involved.
3. The current given is 4 amperes and the voltage given is 12 volts.
4. Multiplying gives 4 times 12, which is 48.
5. The unit of power is the watt, so the heater dissipates 48 watts.
6. Adding the two numbers gives 16 and dividing them gives 3, so both of those options come from the wrong operation.
_Source: Siyavula Physical Sciences Grade 11 (Everything Science, CC BY 4.0), Chapter 11: Electric circuits_
Related questions
Household electricity is sold in units of one kilowatt hour. What does one kilowatt hour mA lamp dissipates 60 watts and is left on for 120 seconds. How much electrical energy doesHow is the equivalent resistance of several resistors joined in series worked out?Three resistors are connected side by side across the same cell. Which quantity is the samThree resistors are joined one after another in a single loop with a cell. How does the cuThe filament of a light bulb gets much hotter as the supply voltage rises, so its resistanOhm's law describes a metal conductor only while which quantity is held constant?