Question

The magnetic field at the center of a long solenoid having 400 turns per unit length and carrying a current $I = 6.24 \times 10^{-7$ A is}

• A. $1.56 \times 10^{-3}$ T
• B. $2.4 \times 10^{-3}$ T
• C. $2.6 \times 10^{-3}$ T
• D. $1.6 \times 10^{-3}$ T

Hint:

For solenoids, remember the formula for the magnetic field and ensure you use the correct value of $\mu_0$.

Answer 1

The Correct Option is A

The magnetic field at the center of a solenoid is given by the formula: $$ B = \mu_0 n I $$ where $n$ is the number of turns per unit length, $I$ is the current, and $\mu_0$ is the permeability of free space. Substituting the given values, we get the magnetic field to be $1.56 \times 10^{-3}$ T.