Question

A coil of insulated wire is connected to a galvanometer. What would be observed if a strong bar magnet with its south pole towards one face of the coil is moved quickly toward it? Name the phenomena involved. State the conclusion based on the observations.

Answer 1

Step 1: Fleming's Right-Hand Rule

1. According to Fleming's RIght-Hand Rule, the thumb represents the motion of the conductor, the index finger represents the direction of the magnetic field and the middle finger represents the direction of the current.
2. All three directions of motion, magnetic field, and current are mutually perpendicular to each other.

Step 2: Deflection of Galvanometer

According to Fleming's Right-Hand rule, if a strong bar magnet with its south pole towards one face of the coil is moved quickly toward it the galvanometer will deflect towards the left side.

Step 3: Phenomenon Involved

1. The phenomenon involved here is called electromagnetic induction.
2. Electromagnetic induction occurs in a time-varying magnetic field.
3. In $1831$, Faraday showed experimentally that whenever the magnetic flux linked with a closed circuit changes with time an electric current is induced in the circuit.
4. This phenomenon is known as electromagnetic induction.
5. It has played an important role in the technological development we find today.

Step 4: Conclusion

1. From the given observation we can conclude that an electric current induces inside the coil when the magnet moves with respect to time.
2. This induced current is present as long as the magnetic field around it due to the bar magnet is varied.