?   in a circuit is the amount of work being done per unit of time.a.Currentb.Capacitancec.Inductanced.Power

Break Down the Problem

1. Identify the key terms in the question.
2. Determine the correct concept related to the amount of work being done per unit of time in an electrical context.

Relevant Concepts

1. The definition of power in electrical terms: Power is the rate at which work is done or energy is transferred in a circuit.
2. The formula for power, $P$, is given by: $P = \frac{W}{t}$ where $W$ is the work done, and $t$ is the time.

Analysis and Detail

1. Examine the four options:
   • Current (a): Refers to the flow of electric charge.
   • Capacitance (b): Refers to the ability of a system to store charge.
   • Inductance (c): Refers to the ability of a conductor to oppose a change in current.
   • Power (d): The rate at which work is done or energy is transferred.

Since power specifically relates to the rate of doing work, it is the correct choice.

Verify and Summarize

• The definitions of current, capacitance, and inductance do not pertain to work done over time.
• Power directly refers to this concept.

Final Answer

The correct answer is d. Power. Power in a circuit is defined as the amount of work being done per unit of time.