Question

The magnetic field inside a current-carrying coil increases when

a) current is increased.
b) an iron core is inserted.
c) the number of loops of wire in the coil increases.
d) all of the above

Answer 1

The magnetic field inside a current-carrying coil increases due to an increase in current, insertion of an iron core, or an increase in the number of wire loops.

Step-by-step explanation:

The magnetic field inside a current-carrying coil increases when current is increased, an iron core is inserted, or the number of loops of wire in the coil increases. Each of these changes impacts the magnetic field in a way that leads to an increase.

Additionally, increasing the number of loops in the coil without changing the current increases the total magnetic flux, hence increasing the field strength inside the coil.

All these factors are aligned with the principle that the induced current in a circuit responds to the change in magnetic flux through various means such as changing the magnetic field strength, the size of the wire loop, and the orientation of the wire loop as described in Lenz's law. This law states that an induced current will always flow in a direction that will oppose the change that produced it. The right-hand rule (RHR-2) can also be applied to determine the direction of the induced current when such changes occur.