Question

A constant current flows in a horizontal wire in the plane of the paper from east to west as shown in figure. Where will the direction of magnetic field be from North to South ?

• A. directly above the wire
• B. directly below the wire
• C. at a point located in the plane of the paper, on the north side of the wire
• D. at a point located in the plane of the paper, on the south side of the wire

Answer 1

The correct option is B directly below the wire

Answer is B
The Fleming's right-hand rule shows the direction of induced current when a conductor moves in a magnetic field. The right hand is held with the thumb, first finger and second finger mutually perpendicular to each other (at right angles).The Thumb represents the direction of Motion of the conductor. The First finger represents the direction of the Field (north to south). The Second finger represents the direction of the induced or generated Current (the direction of the induced current will be the direction of conventional current; from positive to negative).
Therefore, if the right hand is held facing the ground the induced current is along the second finger from east to west direction and the magnetic field in north south direction then the magnetic field will act directly below the wire.