18. Which does not affect the strength of an electromagnet?

A the current in the solenoid

B the temperature of the coil

OC the number of loops in the coil

D the type of ferromagnetic core

The temperature does not affect the strength of a magnet

Explanation:

An electromagnet is obtained by winding an insulated wire round a soft iron rod with the wire ends connected to a DC source. such magnets have temporary magnetic properties which disappears with time as the current supply is cut off.

Furthermore the strength off an electromagnet

increases as current increases increases as the number of turns increases the type of magnetic core is highly essential as an iron core will do batter than a silver core