# What is the formula for the magnetic field due to a solenoid?

Magnetic field in a solenoid formula is given as B = μ0 nl. In the formula, B represents the magnetic flux density, μ0 is the magnetic constant whose value is 4π x 10-⁷ Hm or 12.57 x 10−⁷ Hm, N represents the number of turns, I is the current flowing through the solenoid.

## How do you calculate the emf of a solenoid?

EMF = Magnetic flux density x Width x Speed. This is because speed = distance / time.

## How do you calculate the number of turns on a solenoid?

And we find that the number of turns in a solenoid is equal to its length times the magnetic field strength at its center divided by 𝜇 naught times the current in the solenoid 𝐼.

## Why does the aluminum ring pop up?

So, why does the aluminum ring jump up like that? The coil makes a changing magnetic field that then induces an electric current in the ring. This electric current in the ring then interacts with the magnetic field to make it repel.

## What is N in the formula of solenoid?

Magnetic Field In A Solenoid Formula N denotes the number of turns the solenoid has. More the number of loops, stronger is the magnetic field.

## What is the value of magnetic field inside a solenoid?

Hence the magnetic field is considered to be practically zero because the magnetic field outside the solenoid is so feeble. For an ideal solenoid, its value will be zero. Q.

## What is induced emf formula?

The induced emf is ε = – d/dt (BA cos θ). The magnitude of the magnetic field can change with time.

## How do I calculate emf?

EMF formula can be expressed as, e = IR + Ir or, e = V + Ir, where, e is the electromotive force (Volts), I = current (A), R = Load resistance, r is the internal resistance of the cell measured in ohms.

## How do you calculate the number of turns per unit length solenoid?

We can see that the number of turns per unit length must be equal to the total number of turns, capital 𝑁, divided by the total length, capital 𝐿.

## How do you calculate the number of turns?

If you know the number of turns in the secondary coil and primary and secondary voltages. You can find out the number of turns in the primary using this formula: Np/Ns = Vp/Vs.

## How do you calculate the number of turns in a magnetic field?

In the above expression for the magnetic field B, n = N/L is the number of turns per unit length, sometimes called the “turns density”.

## Why does ring move away from the magnet?

Lenz’s law dictates that if you approach the ring with the north end of the cow magnet, then the direction of the magnetic field due to the induced current in the ring is such that the north pole faces the north end of the magnet, and the two magnetic fields repel each other. This pushes the ring away from you.

## Why does a metal ring expand when heated?

Detailed Solution. When a ring of metal is heated, the hole in the ring expands due to the expansion of the metal. This is because heat supplies energy to the molecules of the metal which then begin to vibrate and move away from each other which in turn leads to an increase in the surface area of the metal.

## Why does the ring follow the magnet?

The electricity in the ring is called an eddy current. The eddy current causes the metal ring to become a magnet. The two electromagnets are arranged so that their north poles point at each other. Two north poles repel each other, so the base and the ring push each other away.

## What is N in magnetic field of solenoid?

A solenoid is a coil of wire designed to create a strong magnetic field inside the coil. By wrapping the same wire many times around a cylinder, the magnetic field due to the wires can become quite strong. The number of turns N refers to the number of loops the solenoid has.

## What is a solenoid class 12 physics?

The solenoid is a coil of wire that acts like an electromagnet when a flow of electricity passes through it.

## Is magnetic field constant in a solenoid?

The magnetic field inside a solenoid is proportional to both the applied current and the number of turns per unit length. There is no dependence on the diameter of the solenoid, and the field strength doesn’t depend on the position inside the solenoid, i.e., the field inside is constant.

## Is magnetic field inside a solenoid is zero?

The magnetic field lines exist outside the solenoid, but the number of field lines per unit area (flux) outside the solenoid is much less compared to the number of lines per unit area (flux) inside the solenoid. Hence the magnetic field outside is so weak that it is considered to be practically zero.

## Why magnetic field is half at the end of solenoid?

Q. Assertion :The magnetic field at the ends of a very long current carrying solenoid is half of that at the centre. Reason: If the solenoid is sufficiently long, the field within it is uniform.

## What is the formula of magnetic field?

B = μ 0 I 2 π r In the equation, µ0 is a special constant known as the permeability of free space(µ0=4π×10-7 T⋅ m/A). Materials with higher permeability possess the ability to concentrate on magnetic fields. The magnetic field has direction as it is a vector quantity.

## How do you find the north and south pole of a solenoid?

We can bring the North pole of a bar magnet closer to both the ends of the currnt carrying solenoid. The end which will repel the North pole of the bar magnet will be the North pole na dthe end of the solenoid which attracts the North pole of the bar magnet will be its South pole.

## What is the formula for magnetic moment?

τ=p×B. The SI unit for magnetic moment is clearly N m T−1. τ=IA×B.

## Where is magnetic field maximum in solenoid?

The net magnetic field is the sum from each individual loop and is maximum in the middle of the solenoid because that point minimizes the average distance to each loop.

## How do you calculate induced emf with resistance?

Then use Ohm’s law as : V=I⋅R⟹I=ϵR V = I ⋅ R ⟹ I = ϵ R , where ϵ is the electromotive force obtained from Step 2, R is the resistance of the coil and I is the current induced in the coil.