Which of the following represents a volt?

Options

A. Joule/second
B. Watt/Ampere
C. Watt/Coulomb
D. Coulomb/Joule

Explanation

To determine which of the following represents a volt, we need to understand the definition and the units associated with it.

### Step-by-Step Solution:

1. **Definition of Volt**: A volt (V) is defined as the unit of electric potential difference or electromotive force. It measures how much potential energy is available to move a unit charge between two points in an electric field.

2. **Potential Energy**: The potential (V) can be expressed in terms of potential energy (U) and charge (Q). The relationship is given by the formula:
\[ V = \frac{U}{Q} \]
where:
- \( V \) is the voltage in volts,
- \( U \) is the potential energy in joules,
- \( Q \) is the charge in coulombs.

3. **Units of Potential Energy**: The unit of potential energy is joules (J). Therefore, we can rewrite the equation as:
\[ V = \frac{J}{C} \]
where \( C \) is the unit of charge (coulombs).

4. **Relating to Power**: We know that power (P) is defined as the rate of doing work or the rate of energy transfer. The formula for power is:
\[ P = \frac{W}{t} \]
where:
- \( P \) is power in watts (W),
- \( W \) is work done in joules (J),
- \( t \) is time in seconds (s).

5. **Current Definition**: Current (I) is defined as the charge per unit time:
\[ I = \frac{Q}{t} \]
where \( I \) is in amperes (A).

6. **Combining the Equations**: From the power equation, we can express power in terms of voltage and current:
\[ P = V \cdot I \]
Rearranging this gives:
\[ V = \frac{P}{I} \]
Since power is measured in watts (W) and current in amperes (A), we can express voltage as:
\[ V = \frac{W}{A} \]

7. **Conclusion**: Therefore, the unit of volt can be expressed as watts per ampere:
\[ 1 \text{ V} = 1 \frac{\text{W}}{\text{A}} \]

### Final Answer:
The correct representation of a volt is **Watt per Ampere (W/A)**.

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