21.1 Electromagnetic induction copper rod U-shaped magnet X Y A copper rod in a magnetic field A copper rod XY with its ends connected to a galvanometer is placed in between the poles of a U-shaped magnet. Example 1

21.1 Electromagnetic induction An alternating current is induced. The current flows from X to Y when the rod is moving upwards. The current flows from Y to X when the rod is moving downwards. (a) What happens to the galvanometer when the copper rod is made to vibrate up and down (as shown by the blue arrows)? copper rod U-shaped magnet X Y

21.1 Electromagnetic induction (b) (i) How would the result in (a) change if a stronger magnet is used? magnetic field strength induced current deflection of galvanometer

21.1 Electromagnetic induction (b) (ii) How would the result in (a) change if the copper rod is made to vibrate at a faster rate? rate of copper wire cuts through the field lines induced current frequency of induced current and deflection of galvanometer frequency of deflection of galvanometer and

21.1 Electromagnetic induction The copper rod does not cut through the magnetic field lines when it is made to vibrate left and right. The galvanometer would not deflect as no current is induced. (c) What happens to the galvanometer when the copper rod is made to vibrate left and right (as shown by the green arrows)? copper rod U-shaped magnet X Y