Question

Which of the following processes will not produce new magnetic poles ?

• A. Cutting a bar magnet in half
• B. Turning on a current in a solenoid
• C. Running a current through a straight wire
• D. Placing an iron rod in contact with a magnet

Answer 1

Answer: (C)

Running a current through a straight wire

If bar magnet is cut into half, we get two magnets each with magnetic pole pairs.

When current is passed through the solenoid, one end of solenoid acts as the north pole and other as the south pole.

If an iron rod is placed in contact with a magnet, iron rod gets induced magnetic poles.

Only in the case of current carrying straight wire, there is no generation of magnetic poles.