# Question regarding induced e.m.f

• anonymousZ10
In summary, the conversation discusses the possibility of inducing e.m.f in a circuit by switching it on and off. It is mentioned that induced e.m.f is proportional to the rate of change of magnetic flux, so alternating the switches can change the magnetic flux and induce current. However, it is also noted that this method may not be very effective for some circuits and may only result in a small amount of induced e.m.f.
anonymousZ10
can we still induced e.m.f in a circuit if we switch on and off the circuit. Well, since induced e.m.f is proportional to the rate of change of magnetic flux. I guess alternating the switches can changes the magnetic flux of a circuit. Please correct me if I'm wrong ^_^ .

Hello, and welcome to PF!

Yes, you are right. For some circuits, the induced emf might be very small.

You can, but a poor way of inducing current, you can't switch very fast and the coil in your circuit won't make it so perfect, you end up with few milli volts !

TSny said:
Hello, and welcome to PF!

Yes, you are right. For some circuits, the induced emf might be very small.
thank you :D

Noctisdark said:
You can, but a poor way of inducing current, you can't switch very fast and the coil in your circuit won't make it so perfect, you end up with few milli volts !

Ah ! now i get it. why the L.E.D flashes once. Thanks

Noctisdark

## 1. What is induced e.m.f?

Induced e.m.f, or electromotive force, is a phenomenon in which a changing magnetic field creates an electric field and induces a voltage in a conductor.

## 2. How is induced e.m.f different from regular e.m.f?

Regular e.m.f is produced by a source such as a battery, while induced e.m.f is created by a changing magnetic field.

## 3. What factors affect the magnitude of induced e.m.f?

The strength of the magnetic field, the velocity of the conductor, and the angle between the magnetic field and the conductor all affect the magnitude of induced e.m.f.

## 4. What is Faraday's law of induction?

Faraday's law states that the magnitude of the induced e.m.f is directly proportional to the rate of change of the magnetic field and the number of turns in the conductor.

## 5. What are some real-world applications of induced e.m.f?

Induced e.m.f is used in generators to produce electricity, in transformers to change the voltage of an electric current, and in induction cooktops to heat up cooking vessels.

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