Table of Contents
- 1 How can the polarity or direction of an induced current be reversed?
- 2 What happens if a magnet is moved back and forth inside a coil of wire?
- 3 What would happen if the coil was rotated faster?
- 4 What happens if you reverse the current in an electromagnet?
- 5 How can you strengthen an electromagnet?
- 6 What happens if you hold the south pole of one magnet close to the north pole of another magnet?
- 7 Why an emf is induced in the coil as it rotates?
- 8 Why does the galvanometer needle return to zero when the magnet stops moving?
- 9 What are Faraday’s laws of electromagnetic induction?
- 10 What is electromagnetic induction?
How can the polarity or direction of an induced current be reversed?
The direction of the induced voltage is reversed when the magnet is moved out of the coil again. It can also be reversed if the other pole of the magnet is moved into the coil.
What happens if a magnet is moved back and forth inside a coil of wire?
The current produced by electromagnetic induction is greater when the magnet or coil moves faster, the coil has more turns, or the magnet is stronger. If the magnet or coil is moved back and forth repeatedly, alternating current is produced.
What would happen if the coil was rotated faster?
The faster the coil rotates the faster will it cut the magnetic field and the bigger will be the output voltage.
What happens when a magnet is moved relative to a coil?
Magnet and Coil When a magnet is moved into a coil of wire, changing the magnetic field and magnetic flux through the coil, a voltage will be generated in the coil according to Faraday’s Law. The polarity of the induced emf is such that it produces a current whose magnetic field opposes the change that produces it.
How do you reverse the direction of the magnetic field in an electromagnet?
Reversing The Polarity Of an Electromagnet:
- Determine the poles of the magnet and mark them accordingly (N=North, S=South)
- Turn off the power switch.
- Use a tool (pliers/screwdriver) to disconnect the two wires.
- Switch the positions of the wires.
- Turn the power back on and test the polarity.
What happens if you reverse the current in an electromagnet?
If you reverse the current you reverse the polarity of the field. The strength of the electro-magnet can be improved by the following: increasing number of coils. increasing the current.
How can you strengthen an electromagnet?
You can make an electromagnet stronger by doing these things:
- wrapping the coil around a piece of iron (such as an iron nail)
- adding more turns to the coil.
- increasing the current flowing through the coil.
What happens if you hold the south pole of one magnet close to the north pole of another magnet?
The other end is called the south pole. When two magnets are brought together, the opposite poles will attract one another, but the like poles will repel one another. This is similar to electric charges. Like charges repel, and unlike charges attract.
What happens if motor back emf is 0?
As the back emf vanishes zero, the whole supply voltage appears across armature and heavy current flows. If supplying unit didn’t trip down by this time, excess current in armature may heat up the armature and it may cause burning of armature winding.
Can you generate emf without rotating the coil Class 12?
(c) Yes, it is possible to generate emf without rotating the coil. Instead of rotation, if coil is allowed to move with velocity ⊥r to field, then also motional emf is induced. Also, by changing A and B, emf is induced.
Why an emf is induced in the coil as it rotates?
Hint: Induced emf is generated in a rotating coil when the angle between area vector and magnetic field changes continuously, hence changing the amount of magnetic flux through the coil. EMF or electromotive force is said to be induced when the flux linking with a conductor or coil changes.
Why does the galvanometer needle return to zero when the magnet stops moving?
When the magnet stops moving and is held stationary with regards to the coil the needle of the galvanometer returns back to zero as there is no physical movement of the magnetic field.
What are Faraday’s laws of electromagnetic induction?
Michael Faraday formulated two laws on the basis of the above experiments. These laws are called Faraday’s laws of electromagnetic induction. Any change in the magnetic field of a coil of wire will cause an emf to be induced in the coil.
What does Faraday’s second law state?
Faraday’s Second Law of Electromagnetic Induction Faraday’s second law of electromagnetic induction states that The induced emf in a coil is equal to the rate of change of flux linkage. The flux is the product of the number of turns in the coil and the flux associated with the coil.
What is the first law of electromagnetism called?
Faraday’s First Law Faraday’s Second Law Faraday’s Law Application Faraday’s law of electromagnetic induction, also known as Faraday’s law, is the basic law of electromagnetism which helps us to predict how a magnetic field would interact with an electric circuit to produce an electromotive force (EMF).
What is electromagnetic induction?
This phenomenon is known as electromagnetic induction. Michael Faraday proposed the laws of electromagnetic induction in the year 1831. Faraday’s law or the law of electromagnetic induction is the observation or results of the experiments conducted by Faraday.