Two concentric circular coils A and B of radii 10 cm and 6 cm respectively, lie in the same vertical plane containing the north to south direction. coil A has 30 turns and carries a current of 10 A. Coil B has 40 turns and carries a current of 15 A .the sense of the current in A is anticlockwise and clockwise in B for an observer looking at the coils facing west. Give the magnitude and direction of net magnetic field.

The vertical component of earth’s magnetic field at a given place is \(\sqrt { 3 } \)  times its horizontal component. If the total intensity of earth’s magnetic field at a place is 0.4 G , find the value of horizontal component of earths field and angle of dip.

north to south direction.Specify the direction in which the uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.

A straight wire of mass 200g and the length 1.5m carries a current of 2A. It is suspended in mid air by a uniform horizontal magnetic field B. What is the magnitude of B in tesla?

A rigid circular loop of radius r and mass m lies in the x-y plane of a flat table and has a current I flowing in it. At this particular place the earth’s magnetic field is B = Bxi +Bzk. What is the value of I, so that loop starts tilting?