In electrical systems, there are several important equations that describe various aspects of electrical energy. Here are some of the major electrical energy equations:
1. Electrical Power (P)
The electrical power is the rate at which electrical energy is transferred or consumed, and it is given by the equation:
P = V * I
..where P is the power in watts (W), V is the voltage in volts (V), and I is the current in amperes (A). This equation is known as Joule’s law.
2. Electrical Energy (E)
The electrical energy consumed or transferred by an electrical device or system can be calculated by multiplying the power by the time:
E = P * t
..where E is the energy in watt-hours (Wh) or joules (J), P is the power in watts (W), and t is the time in hours (h) or seconds (s).
3. Ohm’s Law
Ohm’s Law relates the voltage, current, and resistance in a circuit. It can be expressed using the equation:
V = I * R
..where V is the voltage across a component in volts (V), I is the current flowing through the component in amperes (A), and R is the resistance of the component in ohms (Ω).
4. Energy Efficiency (η)
The energy efficiency of a device or system is the ratio of useful output energy to the input energy. It can be calculated using the equation:
η = (Useful output energy / Input energy) * 100%
The energy efficiency is often expressed as a percentage.
5. Power Loss (P_loss)
In electrical systems, there may be power loss due to factors like resistance and inefficiencies. The power loss can be calculated using the equation: P_loss = I^2 * R where P_loss is the power loss in watts (W), I is the current flowing through the component or conductor in amperes (A), and R is the resistance in ohms (Ω).
These are some of the major electrical energy equations commonly used in electrical systems and calculations. They help in understanding power consumption, energy transfer, efficiency, and losses in electrical circuits.