Electromagnetism Questions

A coil in the shape of an equilateral triangle of side l is suspended between the pole pieces of a permanent magnet such that is in plane of the coil. If due to a current i in the triangle a torque τ acts on it, the side l of the triangle is :

An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional to :

A very long straight wire carries a current I. At the instant when a charge + Q at point P has velocity , as shown, the force on the charge is :

As per this diagram a point charge +q is placed at the origin O. Work done in taking another point charge - Q from the point A [co-ordinates (0, a)] to another point B [co-ordinates (a, 0)] along the straight path AB is :

As a result of change in the magnetic flux linked to the closed loop shown in the figure, an emf V volt is induced in the loop. The work done (joules) in taking a charge Q coulomb once along the loop is :

As a result of change in the magnetic flux linked to the closed loop shown in the figure, an emf V volt is induced in the loop. The work done (joules) in taking a charge Q coulomb once along the loop is :

If λ v, λ x andλ m represent the wavelengths of visible light, X-rays and microwaves respectively, then :

As a result of change in the magnetic flux linked to the closed loop shown in the figure, an emf V volt is induced in the loop. The work done (joules) in taking a charge Q coulomb once along the loop is :

The velocity of electromagnetic radiation in a medium of permittivity $ϵ$ and permeability $\mu$ is given by:

The magnetic force acting on a charged particle of charge $-2\mu \text{C}$ in a magnetic field of $2\text{T}$ acting in $y$ direction, when the particle velocity is $(2\hat{i}+3\hat{j})\times 10^6{\text{ms}}^{-1}$, is:

Under the influence of a uniform magnetic field, a charged particle moves with constant speed $V$ in a circle of radius $R$. The time period of rotation of the particle: