JEE Main20238 Apr 2023Morning ShiftPhysicsMagnetic Effects of CurrentActual
The magnetic intensity at the centre of a long current carrying solenoid is found to be 1 . 6   × 10 3   A   m - 1 . If the number of turns is 8 per cm , then the current flowing through the solenoid is _ _ _ _ _ _ A .
Correct answer
2
Step-by-step solution
The magnetic intensity H is defined as the product of the number of turns per unit length in a coil n and the current that it carries   I . The magnetic field of a solenoid is given by B = μ 0 n i H = B μ 0 = μ 0 n i μ 0 ⇒ H = n i       . . . ( i )   The given data is H = 1 . 6 × 10 3   A   m - 1 n = 8 per cm Substituting the values in equation (i) ⇒ 1 . 6 × 1000 = 8 1 100 × i ⇒ i = 2   A