BITSAT2019PhysicsMagnetic Effects of CurrentActual
The magnetic field at the centre O of the current-carrying square loop shown in the figure is
Options
- A12 × 10 - 5   T
- B4 × 10 - 5   T
- C4 2 × 10 - 5   T
- D2 2 × 10 - 5   T
Correct answer
C. 4 2 × 10 - 5   T
Step-by-step solution
Given, current through the square loop is 2   A . I = 2   A The given situation is shown in the figure. Magnetic field due to wire A B at the centre O is B A B = μ 0 4 π · I r sin 45 ° + sin 45 ° = 10 - 7 × 2 2 × 10 - 2 1 2 + 1 2 = 2 × 10 - 5   T [Downward to the plane of square loop] Since, magnetic field due to side A B ,   B C ,   C D and D A is same in magnitude and direction. Hence, net magnetic field at O B = 4 × B A B = 4 2 × 10 - 5 &