Question

The magnetic field of a solenoid can be increased by

• A. adding more loops per metre
• B. putting an iron core inside the coil to make an electromagnet
• C. increasing the current
• D. All of the above

Answer 1

Answer: (D)

The magnetic field inside a current carrying solenoid is given by

$B={\mu }_{0}nI$

where $n$ is the number of turns per unit length in the solenoid

$I$ is the current through the wire

Hence increasing current or number of loops per meter would increase the magnetic field in solenoid.

The iron core being a magnet itself is magnetized hence it contributes flux to the solenoid's flux, hence the magnetic field strength.