A Level Physics Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Study for the A Level Physics Exam. Our quiz features flashcards and multiple choice questions, each with hints and explanations. Prepare thoroughly!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What is the correct formula for calculating power?

Power = Work done / Time
Power = Current / Resistance
Power = Voltage / Current
Power = Energy / Time

The correct answer is: Power = Work done / Time

Power is fundamentally defined as the rate at which work is done or the rate at which energy is transferred or converted. The formula for calculating power is derived from this definition. When work is done, it is often described in terms of the energy transferred. Therefore, power can be expressed mathematically by the formula: Power = Work done / Time. This equation signifies that power measures how much work is done over a specific amount of time, illustrating a direct relationship between the two quantities. While there are other relevant equations related to power, they pertain to specific contexts. For instance, the relationship between power, voltage, and current is given by the formula Power = Voltage x Current, which is derived from Ohm's law. However, the context of the question emphasizes the general relationship of work done over time, making the first formula the correct choice here. The other equations provided deal with specific cases relating to electrical power or circuit calculations, rather than the general definition of power in physics. This specificity is crucial for understanding the broader applications of power in different physical contexts.