Question

Ravi performed an experiment in his school laboratory to study the magnetic effect of electric current. He passed electric current through a straight copper conductor placed near a magnetic compass. He observed that the compass needle deflected when current flowed through the conductor. When the direction of current was reversed, the direction of deflection of the compass needle also reversed. Later, Ravi used a solenoid connected to a battery and placed a soft iron core inside it. He observed that the solenoid behaved like a bar magnet when current flowed through it and lost its magnetism when the current was switched off.

State the rule to determine the direction of a (i) magnetic field produced around a straight conductor-carrying current, (ii) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it, and (iii) current induced in a coil due to its rotation in a magnetic field.

A magnetic field is produced around a current-carrying wire. The direction of the magnetic field can be determined using:

List two factors on which the strength of magnetic field at a point due to a current carrying straight conductor depends. State the rule that determines the direction of magnetic field produced in this case.