Two \alpha-particles have the ratio of their velocities as 3:2 on entering the field. If they move in different circular paths, then the ratio of the radii of their paths is

When a positively charged particle enters a uniform magnetic field with uniform velocity, its trajectory can be 1 a straight line 2 or circle 3 a helix.

A charged particle is moving in a cyclotron, what effect on the radius of path of this charged particle will occur when the frequency of the radio frequency field is doubled?

A cyclotron is operated at an oscillator frequency of 12 MHz and has a dee radius R = 50 cm. What is the magnitude of the magnetic field needed for a proton to be accelerated in the cyclotron?

The energy of emergent protons in MeV from a cyclotron having radius of its dees 1.8 m and applied magnetic field 0.7 T is

The magnitude of the magnetic field at the centre of the tightly wound 150 turn coil of radius 12 cm carrying a current of 2 A is

A tightly wound 90 turn coil of radius 15 cm has a magnetic field of 4 x 10-4 T at its centre. The current flowing through it is

Which one of the following statements is correct?

The nature of parallel anti-parallel currents are

A long straight wire carrying current of 30 A rests a table. Another wire AB of length 1 m, mass 3 g carries the same current but in the opposite direction, the wire AB is free to slide up and down. The hight upto which AB will rise is

A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not depend upon

A circular coil of 25 turns and radius 12 cm is placed in a uniform magnetic field of 0.5 T nor-mal to the plane of the coil. If the current in the coil is 6 A then total torque acting on the coil is

The gyromagnetic ratio of an electron in sodium atom is

If the current sensitivity of a galvanometer is doubled, then its voltage sensitivity will be

A moving coil galvanometer can be converted into an ammeter by

If the galvanometer current is 10 mA, resistance of the galvanometer, the maximum current which can be measured by this ammeter is

The conversation of a moving coil galvanometer into a voltmeter is done by

The magnetic moment associated with a circular coil of 35 turns and radius 25 cm, if it carries a current of 11 A is