MHT CET20227 Aug 2022Evening ShiftPhysicsMagnetic Effects of CurrentActual
Two thin long parallel wires of same material are separated by a distance ' r ' Both carry same current ' I ' in the direction. Hence they will ( ₀= permeability of free space.)
Options
- AAttract each other with a force ₀ I^ 2 / 2 r per unit length
- BRepel each other with a force ₀ I^2 /(2 r) per unit length
- CAttract each other with a force ₀ I^2 /(2 r) per unit length.
- DRepel each other with a force ₀ I^2 /(2 r) per unit length
Correct answer
C. Attract each other with a force ₀ I^2 /(2 r) per unit length.
Step-by-step solution
The force per unit length between two long current carrying carrying conductors is F = ₀ i ₁ i ₂ 2 r where d is the distance between the conductors and i ₁ and i ₂ are the currents carried by the conductors. The conductors attract each other if i₁ and i₂ are in the same direction. Magnetic field created by conductor 1 at the location of the conductor 2 and conductor 2 gets attracted towards conductor 1. Since i ₁= i ₂= i F = ₀ i ^2 2 r