Test Preparation on AIEEE Solved Papers Physics 2003

A particle of mass M and charge Q moving with velocity v describes a circular path of radius R when subjected to a uniform transverse magnetic field of induction B.The work done by the field when the particle completes one full circle is :

A particle of charge - 16 x 10-18 coulomb moving with velocity 10 ms-1 along the x-axis enters a region where a magnetic field of induction B is along the y-axis and an electric field of magnitude 104 V/m is along the negative z-axis. If the charged particle continues moving along the x-axis, the magnitude of B is :

2A thin rectangular magnet suspended freely has a period of oscillation equal to T. Now it is broken into two equal halves (each having half of the original length) and one piece is made to oscillate freely in the same field. If its period of oscillation is T', the ratio T'/T is :

A magnetic needle lying parallel to a magnetic field requires VV units of work to turn it through 60. The torque needed to maintain the needle in this position will be