Watts, volts, and amps are key units in electrical systems, and they are interrelated through simple formulas. Here’s what each term means and how to calculate them:

Definitions

Watts (W):
- A measure of power, or the rate at which energy is used or generated.
- Formula: Watts=Volts×Amps
Volts (V):
- A measure of voltage, or the electrical potential difference between two points.
- Formula (rearranged from watts): Volts=Watts/Amps
Amps (A):
- A measure of current, or the flow of electric charge.
- Formula (rearranged from watts): Amps=Watts/Volts

Example Scenarios

1. Calculating Watts

Given: 12 volts and 5 amps.
Solution: Watts=12×5=60 W

2. Calculating Amps

Given: 120 watts and 12 volts.
Solution: Amps=120/12=10 A

3. Calculating Volts

Given: 100 watts and 5 amps.
Solution: Volts=100/5=20 V

Relationship with Ohm’s Law

Ohm’s Law can further connect these terms if resistance (R) is involved: V=I×R

Where:

V = Voltage (volts),
I = Current (amps),
R = Resistance (ohms).

Power in AC Circuits

For alternating current (AC), the relationship includes the power factor (PFPF): Watts=Volts×Amps×PF

Power Factor: A number between 0 and 1 that represents the efficiency of power usage (for purely resistive loads, PF=1).

Watts – Volts – Amps