 # How Does The Average Brightness Of The Light Bulb Depend On The Number Of Loops Of The Pickup Coil?

## Why does the light bulb light up when you move the magnet through the coil?

When current is created by moving a magnet through a coil it is said to be an “induced current.” Faraday’s Law is also called the law of induction.

straight through the coil and not slid down the side of the tube to make the LED light up..

## What does Faraday’s law mean?

Faraday’s law of induction (briefly, Faraday’s law) is a basic law of electromagnetism predicting how a magnetic field will interact with an electric circuit to produce an electromotive force (EMF)—a phenomenon known as electromagnetic induction.

## What relationship can you make between the number of loops and the current produced?

The direction of the change in the magnetic field determines the direction of the current. We can increase the voltage by increasing the number of loops in the circuit. The induced voltage in a coil with two loops will be twice that with one loop, and with three loops it will be triple.

## How do you increase magnetic flux?

There is another way of increasing the flux in the circuit: make the field stronger. This is like bringing a magnet closer to the circuit. So the flux in the circuit changes whether we: move the wire in a steady field or.

## What happens to the induced voltage if you increase the number of loops in the wire?

~The total induced emf is equal to the emf induced in each loop by the changing magnetic flux, multiplied by the number of loops. When you increase the number of loops, you increase the total induced emf, which makes more current flow through the bulb, which causes it to shine more brightly.

## Can a transformer convert AC to DC?

A transformer is built to transfer the energy from one circuit into another circuit by way of magnetic coupling. … An alternating current creates a magnetic flux in the core on its way through the first winding, inducing the voltage in the others. It can convert high and low voltages, it cannot convert AC to DC.

## Do transformers use AC or DC?

Transformers do not pass direct current (DC), and can be used to take the DC voltage (the constant voltage) out of a signal while keeping the part that changes (the AC voltage). In the electrical grid transformers are key to changing the voltages to reduce how much energy is lost in electrical transmission.

## What are the disadvantages of transformer?

Disadvantages of Step-Up TransformersRequires a Cooling System. For all its advantages, this is a major disadvantage of this type of transformer. … Bulky. The size of the transformer increases as the voltage increases. … Works only for AC. The transformer can only be used for stepping up alternating current or AC voltages.

## Why is it called a pickup coil?

A coil of wire doesn’t respond to a magnet field but rather to a change in magnetic flux through its ends. Such a coil is commonly called a pickup coil or a search coil.

When Michael Faraday made his discovery of electromagnetic induction in 1831, he hypothesized that a changing magnetic field is necessary to induce a current in a nearby circuit. To test his hypothesis he made a coil by wrapping a paper cylinder with wire.

## How does the magnetic field of a coil depend on the current in the coil?

A wire coil that is carrying a current produces a magnetic field B( r), where r is the distance from the center of the coil to the field point. The strength of the field B is proportional to the current I in the coil. The strength and direction of the field depend on r. … For large distances both fields fall off as 1/r3.

## How does the average brightness of the light bulb depend on the loop area of the pickup coil?

How does the average brightness of the light bulb depend on the loop area of the pickup coil? The brightness decreases when the loop area of the pickup coil increases.

## What causes electricity to flow in the coil?

If a coil of wire is placed in a changing magnetic field, a current will be induced in the wire. This current flows because something is producing an electric field that forces the charges around the wire. … This “something” is called an electromotive force, or emf, even though it is not a force.

## How do you induce current in a coil?

Electric current can be induced in a coil due to the relative motion between the coil and a magnetic field….AnswerInducing current on a coil by moving the coil in a magnetic field.Inducing current on a coil by by changing the magnetic field across it.More items…•

## What happens when there is a current in the coil?

When we induce a current in the coil, it becomes an electromagnet. One end of the coil is a north pole and the other end is a south pole. When the north pole of our magnet is moving towards the left hand end of the coil, the induced current flows anticlockwise (as we look at the left hand end).

## Which electromagnet is the strongest?

The strongest continuous magnetic fields on Earth have been produced by Bitter magnets. As of 31 March 2014 the strongest continuous field achieved by a room temperature magnet is 37.5 T produced by a Bitter electromagnet at the Radboud University High Field Magnet Laboratory in Nijmegen, Netherlands.

## How does the brightness of the light bulb change if the magnet is moved through the coil more quickly?

The bulb shines more brightly. As the magnet is approaching the coil, the magnetic flux is increasing since the field strength is stronger closer to the magnet. The faster the magnet approaches, the quicker the magnetic flux increases, which causes a greater induced emf and a greater current.

## What happens if you move a magnet near a coil of wire?

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.

## Why is AC used in transformers?

transformer work only on ac supply because A transformer needs an alternating current that will create a changing magnetic field. A changing magnetic field also induces a changing voltage in a coil. This is the basis of how a transformer works: The primary coil is connected to an AC supply.

## What happens when you coil a wire?

Electricity and magnetism are linked phenomena. When you bend the wire into a coil, the magnetic fields around each loop of the coil add up to make a long , thin magnet with north at one end and south at the other. The more loops the coil has, the stronger the magnetic field, while the current is flowing.