A current carrying power line carries current from west to east. Then the direction of the magnetic field 5 m above it is.

Question

Accepted Answer

The correct option is (3):

To determine the direction of the magnetic field produced by a current-carrying wire, we use the Right-Hand Thumb Rule. Imagine holding the wire in your right hand with your thumb pointing in the direction of the current. Your curled fingers will then indicate the direction of the magnetic field lines around the wire.

In this problem, the current-carrying power line carries current from west to east. If we point our right thumb towards the east (the direction of the current), our fingers will curl in such a way that above the wire, they point towards the north. Therefore, the magnetic field 5 m above the power line is directed towards the north. This rule is fundamental in understanding the magnetic effects of electric currents and is crucial for students preparing for exams like NEET and JEE.

The incorrect option is (1) Towards east: This would be the direction of the current, not the magnetic field above the wire. The magnetic field lines form concentric circles around the wire.

The incorrect option is (2) Towards west: This is opposite to the direction of the current. The magnetic field direction is perpendicular to both the current direction and the radial line from the wire.

The incorrect option is (4) Towards south: If the magnetic field was towards the south, it would mean the current was flowing from east to west, which contradicts the problem statement.