AP EAMCET202022 Sep 2020Evening ShiftPhysicsMagnetic Effects of CurrentActual
An infinitely long straight conductor is bent into shape as shown in figure. It carries a current I ~A and the radius of circular loop is r ~m . The magnetic induction at the centre of the circular loop is
Options
- A₀ /( -1) 2 r
- B₀ /( +1) 2 r
- C₀ /(2 -1) 2 r
- D₀ /(2 +1) 2 r
Correct answer
A. ₀ /( -1) 2 r
Step-by-step solution
The given situation is shown in the figure, Net magnetic field at O , B=B due to straight wire P Q (upward) +B due to straight wire C D (upward) +B due to circular wire (downward) aligned & =- ₀ 4 I r - ₀ 4 I r + ₀ I 2 r & =- ₀ I 2 r + ₀ I 2 r = ₀ I 2 r [- 1 +1 ] & = ₀ I 2 r [ -1+ ]= ₀ I( -1) 2 r aligned [downward]