# Converting mechanical to electrical energy

• MrLobster
In summary, the conversation discusses an experiment where a hand crank is used to generate electricity and light up a bulb. The professor also mentions a switch to control the bulb's on and off state. It is observed that the crank becomes harder to turn when the bulb is on, and the reason behind this is explained as the creation of a magnetic force that opposes the motion of the crank. The current generated by the changing magnetic force also creates an opposing EMF, making it more difficult to turn the crank. Another perspective is offered, stating that when the bulb is on, the person turning the crank is essentially providing the energy for the light, making it harder to turn.

#### MrLobster

I was watching an experiment that I don't understand. The professor turned a hand crank that generated electricity to light up a bulb. There was also a switch to turn the bulb on and off. When the bulb was on the crank became harder to turn. I don't really understand why that is. Did it somehow create a magnetic force that opposed the motion of the crank?

MrLobster said:
I was watching an experiment that I don't understand. The professor turned a hand crank that generated electricity to light up a bulb. There was also a switch to turn the bulb on and off. When the bulb was on the crank became harder to turn. I don't really understand why that is. Did it somehow create a magnetic force that opposed the motion of the crank?
The current created by the changing magnetic force also creates an opposing EMF to the magnetic which created the current.

Another way to look at it is this - the energy that lights the bulb is being provided by the person turning the crank. If the bulb is off, you have to do less work and the handle turns easily. When the light is on it feels harder because you're working against the back emf created by the flowing current, as Astronuc has said above.

## What is mechanical energy?

Mechanical energy is the energy possessed by an object due to its motion or position. It can be in the form of kinetic energy (energy of motion) or potential energy (energy of position).

## What is electrical energy?

Electrical energy is the energy carried by electric current. It is the flow of electrons through a conductive material, such as a wire.

## How is mechanical energy converted to electrical energy?

Mechanical energy can be converted to electrical energy through the use of a generator. This device converts mechanical energy, usually in the form of rotational motion, into electrical energy by the principle of electromagnetic induction.

## What are some common examples of converting mechanical to electrical energy?

Some common examples of converting mechanical to electrical energy include wind turbines, hydroelectric power plants, and bicycles with dynamos that generate electricity while pedaling.

## What are the applications of converting mechanical to electrical energy?

Converting mechanical to electrical energy has a wide range of applications, including powering homes and businesses, transportation, and manufacturing processes. It also plays a crucial role in renewable energy production, as it allows us to harness the power of natural resources such as wind, water, and solar energy.