NTA Abhyas JEE Main2020PhysicsMagnetic Effects of CurrentPractice
A wire is bent in the form of a circular arc of radius r with a straight portion A B . If the current in the wire is i , then the magnetic induction at point O is
Options
- Aμ 0 i 2 π r tan ϕ
- Bμ 0 i 2 π r π - ϕ
- Cμ 0 i 2 π r π - ϕ + tan ⁡ ϕ
- Dμ 0 i 2 π r π - tan ⁡ ϕ
Correct answer
C. μ 0 i 2 π r π - ϕ + tan ⁡ ϕ
Step-by-step solution
B = B 1 + B 2 = μ 0 i 4 π r 2 π - 2 ϕ + μ 0 i 4 π d 2 sin ϕ Where cos ϕ = d r d = r cos ϕ B = μ 0 i 4 π r [ 2 π − 2 ϕ + 2 tan ϕ ] B = μ 0 i 2 π r [ π − ϕ + tan ϕ ]