Electrical power is the rate at which electrical energy is transferred by an electric circuit. It is measured in watts (W) and is the product of voltage (V) and current (I) in the circuit.

Formula for Electrical Power

The formula to calculate electrical power is: P = V * I where P is the power in watts, V is the voltage in volts, and I is the current in amperes.

Understanding Electrical Power

When an electrical device is connected to a power source, it converts electrical energy into other forms of energy, such as light, heat, or mechanical motion. The power rating of the device indicates how much electrical energy it can convert per unit time.

Units of Electrical Power

The unit of electrical power is the watt (W). One watt is equal to one joule per second.

Calculating Electrical Power

To calculate the electrical power in a circuit, you need to know the voltage across the circuit and the current flowing through it. Using the formula P = V * I, you can find the power.

Example

If a circuit has a voltage of 12 volts and a current of 4 amperes, then the electrical power would be: P = 12V * 4A = 48W

Study Guide

To understand electrical power, make sure to:

Understand the concept of electrical power and its importance in electrical circuits.
Be familiar with the formula for calculating electrical power: P = V * I
Know the units of electrical power and how to convert between them (e.g., watts to kilowatts).
Practice solving problems involving the calculation of electrical power in various circuits.
Understand the relationship between electrical power, voltage, and current in a circuit.

◂Physics Worksheets and Study Guides High School. Thermodynamics

The resources above cover the following skills:

PHYSICAL SCIENCE (NGSS)

Matter and Its Interactions

Students who demonstrate understanding can:

Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.

Energy

Students who demonstrate understanding can:

Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

Plan and conduct an investigation to provide evidence that the transfer of thermal energy when two components of different temperature are combined within a closed system results in a more uniform energy distribution among the components in the system (second law of thermodynamics).