A horizontal aluminium bar of length and mass rests on two smooth parallel rails

PHYSICS · Multi-part · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism

Problem

A horizontal aluminium bar of length

0.50\,\text{m}

and mass

0.15\,\text{kg}

rests on two smooth parallel rails. A uniform magnetic field of

0.60\,\text{T}

is directed vertically downward, and the bar carries a current of

15\,\text{A}

perpendicular to the field. The coefficient of kinetic friction between the bar and the rails is

0.20

. Take

g = 9.8\,\text{m s}^{-2}

. (i) Calculate the net horizontal force acting on the bar. (ii) Hence determine the magnitude of its acceleration along the rails.