Question

A conductor depicted as AB is moving towards you, out of the plane, with two magnets kept as shown below. (G - galvanometer)

Select the correct option regarding polarity of the magnets and the deflection of the galvanometer.

• A. Green - N; Red-S; G - right
• B. Yellow - N; Blue - S; G - right
• C. Yellow - N; Blue - N; G - left
• D. Green - N; Red-N; G - left

Answer 1

The correct option is A Green - N; Red-S; G - right

Using Fleming’s right hand rule, we find that when the conductor is moving towards you, the thumb is taken towards yourself.
Now, when the magnetic field is taken from left to right, the current is in upward direction, or in other words, from B to A. Hence, the current will flow horizontally right from A and downward in the right wire. Hence, the deflection in the galvanometer will be downwards.
Since the direction of magnetic field outside the magnet will be from north pole to south pole, the green segment of the left magnet will be the north pole and the red segment of the left magnet will be the south pole.