Question

Two solenoids are given - 1st has 1 turn per unit length and 2nd has n turns per unit length. Ratio of magnetic fields at their centres is

• A. $n : 1$
• B. $1 : n$
• C. $1 : n^2$
• D. $n^2 : 1$

Answer 1

Answer: (B)

$1 : n$

Answer 2

Magnetic field $\propto$ no. of turns per unit length
$\therefore$ Required ratio = $1 : n$.