Electromagnetics - 3

Particle Motion under O Magntic Field:
(Secondary Information)
= q( + )
If change is projected to the Magnetic Field. The path of the charged particle is purely circular and magnetic force povides necessary centripedal force.


R = Radius of the path.
T = Time period of the path.

Otherwise particle moves in a helical path:
Radius =
Time Period =
Pitch = V₁₁ x T =
where is velocity to magnetic field V₁₁ is velocity 11 to the magnetic field.

Force on a current carrying wire:
(Secondary Information)
As F = q( x )
We can say,
= dq( x )
    
    

dF = I( x )

Torque on a Current Carrying Loop:
Net force on a closed loop is always zero. But there is always a net torque acting on the loop.
Given by
= Magnetic Moment
= Magnetic Field.

Secondary Information:

Let plane of the loop is inclined at an angle 10 - to magnetic field ( with normal to the plane).



Trque = Bil(sin)b
        = B[l(lb)]sin
        = [µ x B]

Energy:
dV = d

    = µB(cos₁ - cos₂)

U = - .B

Dumb Question:

Q1. A rectangular current loop is in an arbitrary orientation is an external magnetic field. Is any work required to rotate the loop about an axis perpendicular to its plane ?
Ans: No, no work is required.

Q2. two wires are II to each other in an external magnetic field with their in same direction. Will they attract or repet ?
Ans: They will attract each other.

Q3. A particle enters a external magnetic field to it like shown in figure.



In which direction relative to initial air.... will .. leave the field.
Ans: It will complete half circle and leave II to initial direction.