A copper wire of radius 0.6 mm carries a current of 1A. Assuming the current to be uniformly distributed over a cross sectional area, find the magnitude of current density.

A wire carries a current of 0.3 A. Calculate the charge passing through the cross section of the wire in two minutes.

A circular loop of radius 9.7 cm carries a current 2.3A. Obtain the magnitude of the magnetic field:- centre of the loop .

A semicircular arc of radius 20 cm carries a current of 10 A calculates the magnitude of magnetic field at the centre of the arc.

A wire carries a current of 0.1 A. Find the time interval during which a charge of 5 C passes through the cross section of the wire.

A circular coil of 30 turns and radius 8.0 cm carrying a current of 6.0 A is suspended vertically in a uniform horizontal magnetic field of magnitude 1.0 T. The field lines make an angle of 60^@ with the normal of the coil. Calculate the magnitude of the counter torque that must be applied to prevent the coil from turning.

A semicircular arc of radius 10 cm carrying current of 20 A. Calculate the magnitude of magnetic field at the centre of arc. What will be the direction of magnetic field of current flows in anticlockwise direction?

A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of the magnetic field due to the current1.5 m below the line?

A solenoid of 150 cm length having 300 turns carries a current of 4A. Find the magnitude of the magnetic field inside the solenoid.

A circular loop has radius 10 cm and it is carrying a current of 0.1A. Calculate magnetic dipole moment.

A straight wire of length 0.5 m carrying a current of 1.6 ampere is placed in a uniform magnetic field of induction 2 T. If the magnetic field is perendicular to the length of the wire, then force on the wire is