Current is induced in coil due to motion of the current carrying coil . In Fig. the bar magnet is replaced by a second coil connected to a battery. The steady current in the coil produces a steady magnetic field. As coil is moved towards the coil , the galvanometer shows a deflection. This indicates that electric current is induced in coil . When is moved away, the galvanometer shows a deflection again, but this time in the opposite direction. The deflection lasts as long as coil is in motion. When the coil is held fixed and is moved, the same effects are observed. Again, it is the relative motion between the coils that induces the electric current. What would you do to obtain a large deflection of the galvanometer? How would you demonstrate the presence of an induced current in the absence of a galvanometer?
A square loop of side and resistance is placed vertically in the east-west plane. A uniform magnetic field of is setup across the plane in the north-east direction. The magnetic field is decreased to zero in at a steady rate. Determine the magnitudes of induced emf and current during this time-interval.
A circular coil of radius turns and resistance is placed with its plane perpendicular to the horizontal component of the earth’s magnetic field. It is rotated about its vertical diameter through in . Estimate the magnitudes of the emf and current induced in the coil. Horizontal component of the earth’s magnetic field at the place is .
The figure below shows planar loops of different shapes moving out of or into a region of a magnetic field which is directed normal to the plane of the loop away from the reader. Determine the direction of induced current in each loop using Lenz’s law.
A metallic rod of length is rotated with a frequency of . with one end hinged at the centre and the other end at the circumference of a circular metallic ring of radius about an axis passing through the centre and perpendicular to the plane of the ring .A constant and uniform magnetic field of parallel to the axis is present everywhere. What is the emf between the centre and the metallic ring?
A wheel with metallic spokes each long is rotated with a speed of in a plane normal to the horizontal component of earth’s magnetic field at a place. If at the place, what is the induced emf between the axle and the rim of the wheel? Note that .
The arm of the rectangular conductor is moved from , outwards. The uniform magnetic field is perpendicular to the plane and extends from to and is zero for . Only the arm possesses substantial resistance . Consider the situation when the arm is pulled outwards from to , and is then moved back to with constant speed . Obtain expressions for the flux, the induced , the force necessary to pull the arm and the power dissipated as joule heat. Sketch the variation of these quantities with distance.