The magnetic field at a point inside the solenoid of infinite length is given by B=___________. (here ′n′′𝑛′ is the number of turns per unit length)

The magnetic field $B$ inside a long solenoid can be expressed using the formula:

$B = \mu_0 n I$

Explanation of the Formula:

1. Magnetic Constant ($\mu_0$): This is the permeability of free space, which is a constant value approximately equal to $4\pi \times 10^{-7} \, \text{T m/A}$.

2. Turns per Unit Length ($n$): This is the number of turns (loops of wire) per unit length of the solenoid.

3. Current ($I$): This refers to the electric current flowing through the solenoid.

Summary:

Therefore, to fill in the blank for the magnetic field at a point inside the solenoid of infinite length, we can conclude:

$B = \mu_0 n I$

This formula indicates that the magnetic field inside an ideal solenoid is uniform and directly proportional to the current and the number of turns per unit length.