BITSAT2012PhysicsMagnetic Effects of CurrentActual
A horizontal overhead powerline is at height of 4 ~m from the ground and carries a current of 100 ~A from east to west. The magnetic field directly below it on the ground is ( ₀=4 10⁻⁷ Tm A ⁻¹ )
Options
- A2.5 10⁻⁷ ~T southward
- B5 10⁻⁶ T northward
- C5 10⁻⁶ ~T southward
- D2.5 10⁻⁷ T northward
Correct answer
C. 5 10⁻⁶ ~T southward
Step-by-step solution
The magnetic field is B = ₀ 4 2 I r =10⁻⁷ 2 100 4 =5 10⁻⁶ ~T According to right hand palm rule, the magnetic field is directed towards south.