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. \( 1 : n \)
• B. \( 1 : n^2 \)
• C. \( 1 : n \)
• D. \( n^2 : 1 \)

Hint:

The magnetic field inside a solenoid is directly proportional to the number of turns per unit length.

Answer 1

The Correct Option is A

Step 1: Magnetic Field in Solenoid.
The magnetic field inside a solenoid is directly proportional to the number of turns per unit length. For the first solenoid, the magnetic field will be proportional to 1, and for the second solenoid, it will be proportional to \(n\). Thus, the ratio of magnetic fields at the centers is \( 1 : n \).
Step 2: Conclusion.
The correct answer is (A), \( 1 : n \).