Magnetic Effects of Current

Assertion : A charge particle is released from rest in a magnetic field then it will move in circular path. Reason : Work done by a magnetic field on the charged particle is non zero.

The magnetic field $(B)$ inside a long solenoid having $n$ turns per unit length and carrying current $I$ when iron core is kept in it is ($\mu_0=$ permeability of vacuum, $\chi=$ magnetic susceptibility)

Force on a current carrying closed loop (Radius $=R$) in a uniform magnetic field $(B)$ which is at an angle $30^{\circ}$ with the normal will be

A proton of velocity $(3 \hat{i}+2 \hat{j}) \mathrm{m} \mathrm{s}^{-1}$ enters a field of magnetic induction $(2 \hat{j}+3 \hat{k})$ tesla. The acceleration produced in the proton in $\mathrm{m} \mathrm{s}^{-2}$ is…

Find force per unit length at $P$.

A proton is projected with velocity $\vec{v}=2 \hat{i}$ in a region where magnetic field $\vec{B}=(\hat{i}+3 \hat{j}+4 \hat{k}) \mu \mathrm{T}$ and electric field $\vec{E}=10 \hat{i} \mu \mathrm{Vm}^{-1}$. Then find out…

A semicircular arc of radius $r$ and a straight wire along the diameter, both are carrying same current $i$. Find out magnetic force per unit length on the small element $P$, which is at the centre of curvature.

Two parallel infinitely long current carrying wires are shown in figure. If resultant magnetic field at point $P$ is zero. Then determine current $I$.

Assertion : When radius of a circular loop carrying current is doubled, its magnetic moment becomes four times. Reason : Magnetic moment depends on area of the loop.

In the cyclotron, as radius of the circular path of the charged particle increases $(\omega=$ angular velocity, $v=$ linear velocity)

Assertion : Magnetic field can not change kinetic energy of a moving charge. Reason : Magnetic field can not change velocity vector.

Two magnets are suspended by a given wire one by one. In order to deflect the first magnet through $45^{\circ}$, the wire has to be twisted through $540^{\circ}$ whereas with the second magnet, the wire requires a twist…