MHT CET Medical202624 April 2026Evening ShiftPhysicsMagnetic Effects of CurrentActual
The magnetic flux near the axis and inside the air core solenoid of length 60 cm carrying current 'I' is 1.57 10⁻⁶ Wb . Its magnetic moment will be cross-sectional area of a solenoid is very small as compared to its length, ₀ = 4 10⁻⁷ SI unit
Options
- A0.25 Am ^2
- B0.50 Am ^2
- C0.75 Am ^2
- D1.00 Am ^2
Correct answer
C. 0.75 Am ^2
Step-by-step solution
The magnetic field inside a long solenoid is given by: B = ₀ N I L where N is the total number of turns, I is the current, and L is the length of the solenoid. The magnetic flux through the cross-section of the solenoid is: = B A = ₀ N I A L The magnetic moment of a solenoid is given by: M = N I A Substituting M into the flux equation, we get: = ₀ M L Rearranging to solve for the magnetic moment M : M = L ₀ Given values are: = 1.57 10⁻⁶ Wb L = 60 cm = 0.6 m ₀ = 4 10⁻⁷ T m/A = 4 3.14 10⁻⁷ T m/A = 12.56 10⁻⁷ T m/A Su