MHT CET202014 Oct 2020Evening ShiftPhysicsMagnetic Effects of CurrentActual
Two parallel wires of equal lengths are separated by a distance of 3 ~m from each other. The currents flowing through first and second wire is 3 ~A and 4.5 ~A respectively in opposite directions. The resultant magnetic field at mid-point of both the wires is ( ₀= . permeability of free space)
Options
- A3 ₀ 2
- B7 ₀ 2
- C₀ 2
- D5 ₀ 2
Correct answer
D. 5 ₀ 2
Step-by-step solution
The currents are in opposite direction and hence their fields are in same direction at the mid point which is at a distance of 1.5 ~m from each wire. aligned B ₁ &= ₀ 2 I ₁ r = ₀ 2 3 1.5 = 2 ₀ 2 B ₂ &= ₀ 2 I ₂ r = ₀ 2 4.5 1.5 = 3 ₀ 2 B &= B ₁+ B ₂= 5 ₀ 2 aligned