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When a strong magnet is passed rapidly through a coil of wire what is true?
The magnetic field lines (the lines of force) around the magnet sweep the windings in the coil. This induces a voltage in the windings (through induction), and the voltage will try to drive current if it can. There is a bit more to this, but the essential elements are that the magentic lines of force cause voltage in the coil because there is relative motion between the field and the coil.
Does adding electric currents to something that is already magnetized increase or decrease the power of the magnet?
By 'adding electric currents', you are presumably talking about passing a d.c. current through a coil wound around a magnet?First of all, you cannot increase the flux density of a magnet beyond saturation, regardless of the current or number of turns that make up the coil. Whether on not you increase or reduce the flux density depends on the polarity of the coil compared with the polarity of the magnet; if they are opposite then, yes, you can demagnetise the magnet and, in fact, remagnetise it in the opposite direction.
How an analog volt meter works?
The meter movement has a current flowing through a coil. That coil is on a magnet. The electromagnet with the needle moves according to the current flow. That flow is established by resistive ladders inside the meter.
Is there a pulsating current dc transformer?
Yes, an example is an automobile's ignition coil, which is energised from the battery, via the contacts within the distributor. The contacts open and close, supplying the ignition coil with pulsating current.
Can you let rotate magnets by themselves to generate electricity?
A magnet rotating inside a coil of wire will induce a current in the wire. Disassemble a bicycle generator and that is what you will find inside, a magnet attached to the input axle surrounded by a coil. The current generated will be alternating current because the magnetic field reverses every 1/2 rotation. Frequency will depend on the speed of the input axle, which is of course dependent on the speed of the bicycle itself.
What is the purpose of the permanent magnet in the moving coil meter?
The purpose of the permanent magnet in the moving coil meter is to measure electrical current. The coil will have a magnetic field which will react to the magnetic field of the permanent magnet. Since opposite poles attract, it will cause for the coil to move.Ê
What happens when a magnet is moved towards a coil?
You will generate electricity. As the wire cuts through the magnetic field.As the magnet is moved, there will be an induced electro-motive force (EMF) which can cause a current in the coil. Once the magnet stops moving, the current will go to zero.
When does a magnet induce an electric current in a wire coil?
A magnet induces an electric current in a wire coil when there is a relative motion between the magnet and the coil, which generates a changing magnetic field. This changing magnetic field induces an electromotive force, leading to the flow of an electric current in the wire coil.
How can you use a magnet to induce a current?
You can induce a current in a wire by moving the magnet in and out of the coil or by moving the coil near the magnet. The changing magnetic field created by the moving magnet induces a current in the wire according to Faraday's law of electromagnetic induction.
What is a magnet created when electric current flows through a coil of wire?
A magnet created when electric current flows through a coil of wire is called an electromagnet.
Moving a magnet in and out of a coil of wire produces an?
electric current in the coil of wire.
How can the magnetism of a permanent magnet be weakened or removed?
Put it in a coil which has an alternating current in it. The AC current produces a magnetic field in the coil which alternates with the changing voltage. This changes the magnetism of the permanent magnet. Gradually reduce the current in the coil and the permanent magnet will end up unmagnetised.
How does the voice coil interacts with the magnet on the very bottom of the speaker?
The magnet is permanent, and the voice coil magnetism alternates with the current, pushing the cone outward against the magnet or pulling it inward towards the magnet as the current changes direction.
What happen in coil of wire when you pass a magnet through it?
A current would be induced in the coil.
Can a magnet cause an electric current to flow through a wire?
Yes, a magnet can induce an electric current to flow through a wire. When a magnet moves near a wire, it creates a changing magnetic field that induces an electric current in the wire through a phenomenon called electromagnetic induction.
Would applying current through a coil which has a permanent magnet at its center increase the magnetic field from the magnet?
No, applying current through a coil around a permanent magnet will not increase the magnetic field generated by the magnet. The magnetic field of a permanent magnet is independent of external factors such as current flowing through a coil.
What will happen to the current if the magnet and coil were not moving?
If the magnet and coil are not moving relative to each other, there will be no induced current in the coil. The movement of the magnetic field relative to the coil is required to induce an electromotive force and generate current through electromagnetic induction.
