KVPY2018PhysicsMagnetic Effects of Current
The current in flowing along the path A B C D of a cube (shown in the left figure) produces a magnetic field at the centre of cube of magnitude B . Dashed line depicts the non-conducting part of the cube. Consider a cubical shape shown to the right which is identical in size and shape to the left. If the same current now flows in along the path D A E F G C D , then the magnitude of magnetic field at the centre will b
Options
- Azero
- B2 B
- C3 B
- DB
Correct answer
C. 3 B
Step-by-step solution
Given magnetic field due to a square loop D A B C A at centre of cube is B . Now, loop D A E F G C D can be viewed as super position of three square loops as shown below. So, net field at centre = resultant of fields of these three loop ∴ B net = B i ^ + B j ^ - B k ^ Magnitude of resultant field is B net = B 2 + B 2 + B 2 = 3 · B