Question

Discuss the following:
1. Hall effect
2. cyclotrons
3. Torque on a current loop in a uniform Magnetic fields

Answer 1

1) hall effect- lets say we have a steel plate which is connected to a battery so that current passes through it. so when introduce a magnetic field which is perpendicuar to the  the plate, the path of flow of the charge gets disturbed and the positive and negative charges gets accumulated on either side of the plate, meaning positive charges on one side and negative charges on one side . This creates a potential difference and this is called hall effect.

2) cyclotrons-cyclotron is a device which is used to accelerate particles like neutron , deutron , proton etc which is very important in nuclear physics because these accelerated partcles have very high energy which is used to bombard nuclei. Its generally consists of two conducting metals separated by a distance and have two magnets up and below it .The metals are connected to a AC power source to produce an electric between the metals and the two magnets produce an magnetic field perpendicular to the eletric field.Now if we introduce positive charge particle in between the two metals , the charged partcle gets accelerated in a circular path due to the influence of electric and as well magnetic field and achieves a much greater velocity.

3) Torque on a current loop in a uniform magnetic field

lets have a rectangular loop and a current (I) is going along the loop, the length of rectangle is L , let this be placed in uniform magnetic field B.We should note that the torue on the upper and bottom part of the loop experiences no torque since they will be parallel to magnetic field and we know that torque since they their forces cancel out each other because of the formula

T=IBAsin and sin 0=1

the left and right side of the loop produces torque because they have a coupling effect on the loop because the forces on the sides acts inwards and outwards even tho they also have same magnitude and opposite direction