AP EAMCET202018 Sep 2020Evening ShiftPhysicsMagnetic Effects of CurrentActual
A charge (q ) moving in a circle of radius (r ) metre makes (n ) rev/s. Magnetic field at the centre of the circle is
Options
- A( 2 q n r 10⁻⁷ NA ⁻¹ ~m ⁻¹ )
- B( 2 q r 10⁻⁷ NA ⁻¹ ~m ⁻¹ )
- C( 2 n q r 10⁻⁷ NA ⁻¹ ~m ⁻¹ )
- D( 2 q r NA ⁻¹ ~m ⁻¹ )
Correct answer
C. ( 2 n q r 10⁻⁷ NA ⁻¹ ~m ⁻¹ )
Step-by-step solution
Current associated due to the movement of charge (q ) in circular path of radius (r ) is given as ( aligned I & = q T = q ( 1 n ) [ T= 1 n ] & =q n aligned ) ( ) Magnetic field at the centre, (B= ₀ I 2 r ) ( aligned & = ₀ q n 2 r = (4 10⁻⁷ ) q n 2 r & = 2 n q r 10⁻⁷ NA ⁻¹ ~m ⁻¹ aligned )