Question

Describe Oersted's experiment to show that a magnetic field is produced around a current carrying conductor wire.

Hint:

Right-Hand Thumb Rule: If the thumb points in the direction of current, the curled fingers show the direction of magnetic field lines.

Answer 1

Step 1: Background
Before Oersted’s discovery (1820), electricity and magnetism were considered two separate phenomena. Hans Christian Oersted’s experiment showed for the first time that an electric current can produce a magnetic field, thus linking electricity and magnetism.
Step 2: Apparatus Required
A straight conducting wire.
A stand to hold the wire horizontally.
A battery to pass current.
A key (switch).
A magnetic compass needle.
Step 3: Procedure
Place the straight conducting wire above a magnetic compass needle.
Connect the wire to the battery and key.
When no current flows, the compass needle points in the north-south direction (Earth’s magnetic field).
Now close the key to allow current through the wire.
It is observed that the compass needle gets deflected from its north-south direction.
The deflection changes when the direction of current is reversed.
Step 4: Observation
The compass needle is deflected only when current flows through the wire. This proves that a magnetic field is produced around the conductor. The direction of this magnetic field depends on the direction of current.
Step 5: Conclusion
Oersted concluded that electric current produces a magnetic field around the conductor. The direction of this field is given by the Right-Hand Thumb Rule.
Step 6: Real-Life Applications
Basis of electromagnets and electric motors.
Principle of transformers and generators.
Used in MRI scanners and loudspeakers.
Final Answer:
Oersted’s experiment demonstrated the fundamental principle of electromagnetism — a current carrying conductor produces a magnetic field around it.