Magnetic Effect Of Current NAT Level - 2 - Physics MCQ

Ratio of magnetic field at the centre of a current carrying coil of radius R and at a distance of 3R on its axis is :

Same current i = 2A  is flowing in a wire frame as shown in figure. The frame is a combination of two equilateral triangles ACD and CDE of side 1m. It is placed in uniform magnetic field  B = 4T acting perpendicular to the plane of frame. The magnitude of magnetic force acting on the frame is :

Equal currents i = 1 A are flowing through the wires parallel to y-axis located at  x = +1m, x = +2, x = +4m  etc, but in opposite directions as shown. The magnetic field at origin (in units of   tesla) will be :

A conducting ring of mass 2 kg  and radius 0.5 m  is placed on a smooth horizontal plane. The ring carries a current i = 4A. A horizontal magnetic field B = 10 T is switched on at time t = 0 as shown in figure. The initial angular acceleration (in rad/s²) of the ring will be

Two parallel wires carrying equal currents in opposite directions are placed at x = +a  parallel to y-axis with z = 0. Magnetic field at origin O is B₁ and at P (2a, 0, 0) is  B₂. Then the ratio B₁/B₂  is :

A particle of charge per unit mass α is released from origin with a velocity   in a uniform magnetic field   If the particle passes through (0, y, 0), then y  is equal to  The value of n  is ____.

A charged particle is projected with velocity v₀ along positive x-axis. The magnetic field  B  is directed along negative z-axis between x = 0 and  x = L. The particle emerges out (at  x = L) at an angle of 60° with the direction of projection. Find the velocity with which the same particle is projected (at x = 0) along positive x-axis so that when it emerges out (at  x = L), the angle made by it is 30° with the direction of projection is  nv₀. Find the value of  n.