99 Percentile Qs Bank for JEE MainPhysicsMagnetic Effects of Current
For c = 2 a and a < b < c , the magnetic field at the point P will be zero when
Options
- Aa = b
- Ba = 3 5 b
- Ca = 5 3 b
- Da = 1 3 b
Correct answer
C. a = 5 3 b
Step-by-step solution
Magnetic field at the centre b = μ 0 I 2 c ⊗ + μ 0 I 2 b 3 4 ⊙ + μ 0 I 2 a 3 4 ⊗ As per problem : 0 = μ 0 I 2 1 c - 3 4 b + 3 4 a ⇒ 3 4 1 b - 1 a = 1 c If c = 2 a , 3 4 1 b - 1 a = 1 2 a ⇒ a = 5 3 b