How is power defined?

How is power defined?

• A. Rate of doing work or expending energy
• B. Amount of electric charge stored
• C. Directly proportional to resistance
• D. Total energy in a circuit

Answer: (A)

Power is the rate at which work is done or energy is expended. It tells you how quickly energy is being used or transferred. In electrical terms, power equals voltage times current (P = V × I), which shows energy flow per second through a circuit. The unit is the watt, defined as one joule per second. This concept rules out the other ideas: electric charge stored describes capacity, not rate of energy use. Saying power is directly proportional to resistance is misleading because power depends on both voltage and current; with a fixed voltage, increasing resistance lowers current and power (P = V^2 / R), while with a fixed current, power would increase with resistance (P = I^2 R), so the simple statement isn’t generally correct. And total energy in a circuit refers to energy, not the rate at which energy is used; energy is the integral of power over time.

Power is the rate at which work is done or energy is expended. It tells you how quickly energy is being used or transferred. In electrical terms, power equals voltage times current (P = V × I), which shows energy flow per second through a circuit. The unit is the watt, defined as one joule per second.

This concept rules out the other ideas: electric charge stored describes capacity, not rate of energy use. Saying power is directly proportional to resistance is misleading because power depends on both voltage and current; with a fixed voltage, increasing resistance lowers current and power (P = V^2 / R), while with a fixed current, power would increase with resistance (P = I^2 R), so the simple statement isn’t generally correct. And total energy in a circuit refers to energy, not the rate at which energy is used; energy is the integral of power over time.