What unit symbol is used for energy?

• A. W
• B. J
• C. N
• D. s

Answer: (B)

The unit symbol used for energy is represented by the letter 'J', which stands for joules. The joule is the standard unit of energy in the International System of Units (SI) and is defined as the amount of work done when a force of one newton displaces an object by one meter in the direction of the force. It is also equivalent to one watt-second, which highlights the relationship between power and energy over time.

The other options represent different physical quantities: 'W' stands for watts, which is the unit of power, indicating the rate of energy transfer; 'N' is the symbol for newtons, the unit of force; and 's' stands for seconds, the unit of time. Understanding the distinction between these units is crucial as they serve different roles in the realms of physics and engineering, particularly in electrical science where energy transfer and power calculations are frequent.