KCET2020PhysicsMagnetic Effects of Current
In the given figure, the magnetic field at O .
Options
- A3 4 ₀ I r + ₀ I 4 r
- B3 10 ₀ I r - ₀ I 4 r
- C3 8 ₀ I r + ₀ I 4 r
- D3 8 ₀ I r - ₀ I 4 r
Correct answer
C. 3 8 ₀ I r + ₀ I 4 r
Step-by-step solution
According to the figure, magnetic field at point is given as B_ net = magnetic field due to straight wire A B+ magnetic field due to straight wire C D+ magnetic field due circular wire B C Since, point O is along the length of the wire B A . So, B_ A B =0 aligned B_ net &=0+ ₀ 4 I r + 270 360 ( ₀ I 2 r ) &= ₀ I 4 r + 3 4 ₀ I 2 r &= ₀ I 4 r + 3 ₀ I 8 r ( downward ) aligned