1. Notice that the voltmeter moves in response to the coil entering or leaving the magnetic gap. 2. Let's apply Faraday's Law to this situation. Faraday's Law says that the induced voltage (or emf )in a loop of wire caused by a changing magnetic field is:
€ = 1
Where is the magnetic flux which is
Q = BA
In this case, the flux density B is not changing. Instead, the changing flux is due to the motion of the coil as it enters or leaves the magnetic gap:
do = BdA
Given that the area immersed in the gap is changing as the coil enters the gap, what is the correct expression of Faraday's Law for this situation?

Explanation:

let the coil of length l and breathe b entering the magnetic field B with speed v.

So, the magnetic flux through the coil is

Ф = B(l×b)

length × breathe = area

Ф = BA

dФ = BdA

therefore induced emf is given as

ε =

note:

ε

attached is the diagram for the solution

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

B) raising the temperature and reducing the volume of the gas.|-/