MHT CET Medical202621 April 2026Morning ShiftPhysicsMagnetic Effects of CurrentActual
The magnetic field inside the solenoid is
Options
- Adirectly proportional to its length.
- Bdirectly proportional to current
- Cinversely proportional to current
- Dinversely proportional to total number of turns
Correct answer
B. directly proportional to current
Step-by-step solution
The magnetic field inside a long solenoid is given by the formula: B = ₀ n I where n is the number of turns per unit length ( n = N L ) and I is the current flowing through the solenoid. From the formula, it is clear that the magnetic field B is directly proportional to the current I ( B I ). It is directly proportional to the total number of turns N and inversely proportional to the length L . Thus, the magnetic field is directly proportional to the current. Answer: directly proportional to current