Physics/Magnetism Question

Question

An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. It consists of a solenoid (wire) wrapped around a bar of iron or other ferromagnetic material. A solenoid is a coil of wire with electric current flowing through it. This gives the coil north and south magnetic poles and a magnetic field. The magnetic field of the solenoid magnetizes the iron bar and creates a more powerful magnet. Electromagnets are used as components of other electrical devices as well as in industry to lift or move heavy objects. Which of these would not increase the strength of an electromagnet?

A. adding more coils of wire

B using a larger magnetic core

C. increasing the current flowing through it

D. increasing the distance between the wire and the core

Answer 1

Hello Sri

Let us look at the choices

A. adding more coils of wire

B using a larger magnetic core

C. increasing the current flowing through it

D. increasing the distance between the wire and the core

A. is not true as just adding more coils may not help unless we increase to the number of turns on thesame length

B Is not correct as length of core increased beyond length of solenoid will decrease field at the ends of core

C. It the the correct choice to increase strength of magnetic field at the core of solenoid

D. Increasing the distance will rather decrease the strength at the core

So choice C is correct