HARD
12th Odisha Board
IMPORTANT
Earn 100

An electron makes 3×105 revolutions per second in a circle of radius 0.5 °A. Find the magnetic field at the center of the circle

Important Questions on Magnetic Effect of Electric Current

HARD
12th Odisha Board
IMPORTANT
A semicircular wire of radius 10 cm carries a current 5 A. Calculate the magnetic field at the centre of the circle.
HARD
12th Odisha Board
IMPORTANT
A long cylindrical wire of radius 2.5 mm carries a current of 1A distributed uniformly over its cross-section. Find the magnitude of the magnetic field at a point inside the wire at a distance of 1 mm from the axis.
MEDIUM
12th Odisha Board
IMPORTANT
A long solenoid has closely wound turns such that the successive turns nearly touch each other but well insulated. If the wire used in the solenoid has a radius of 0.5 mm, find the magnetic field at the centre of the solenoid, when it carries a current of 5 A
HARD
12th Odisha Board
IMPORTANT
A magnetic field of 4×10-3k ^tesla  exerts a force of 4i^+3j^×10-10newton on a particle having a charge of 10-9coulumb in X-Y plane Find the velocity of the particle.
HARD
12th Odisha Board
IMPORTANT
A rectangular coil of 100 turns and length of 5 cm and width 4 cm is suspended in a uniform magnetic field with its plane parallel to the field. A torque of 0.2 N m acts on the coil when a current of 0.2 A is maintained in it. Find the magnitude of the magnetic field.
HARD
12th Odisha Board
IMPORTANT
A moving coil galvanometer has a resistance of 30 ohm , through a current of 1mA flows. Find the value of multiplier resistance to be used with the galvanometer to convert it to a voltmeter of the range 2.5 V.
HARD
12th Odisha Board
IMPORTANT
A moving coil galvanometer has a resistance of 30 ohm , through a current of 1mA flows. Find the value of multiplier resistance to be used with the galvanometer to convert it to a voltmeter of the range 10 V.
HARD
12th Odisha Board
IMPORTANT
A rigidly supported long horizontal wire carries a current  Ia= 100 A. Directly above and parallel to it is a fine wire that carries a current Ib=20 A and weigh 0.073 N/m. How far above the lower wire should this second wire be strung so that it may be supported by magnetic repulsion (assume the diameter of the wire is small)