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By taking the voltage and multiplying it by the associated current, the power can be determined. A watt (W) is a unit of power defined as one Joule per second. For a dc source the calculation is simply the voltage times the current: W = V x A.

## How do you calculate input power?

**Input and output power**

- Electrical power is calculated by multiplying voltage (in volts) by current (in amps).
- If a transformer is 100% efficient, then the input power will equal the output power. …
- V
_{P}is input (primary) voltage. - I
_{p}is input (primary) current. - V
_{s}is output (secondary) voltage.

## What is the input power?

Input refers **to the amount of energy put into a device**, and output refers to the amount of energy that comes out. A device may change the type of energy but not the amount. For example, a light bulb’s input energy is the form of electrical energy, and its output energy is in the form of light and heat.

## How do you find the current input?

The factors that determine input current are output power, input voltage, and converter efficiency. **Power = Voltage x Current**. Efficiency = Power Out / Power In.

## Is a motor input or output?

Output

Output device |
Function | Use |
---|---|---|

Motor | Converts power into rotary motion that can turn a spindle linked to gears or wheels to make them move | Cars and trains |

Light-emitting diode (LED) | A long-lasting, low-power light | Torches, lamps and power indicators |

## What does motor output mean?

In psychology, denoting **the organism’s overt reaction to a stimulus** (motor response).

## How do you find power?

**Power is equal to work divided by time**. In this example, P = 9000 J /60 s = 150 W .