An electron completes 3 10^5 revolutions per second in a circle of radius 0.5 angstrom. Determine the magnetic field B at the centre of the circle.

Step-by-step solution

The equivalent current I due to the revolving electron is given by: I = e f Substituting the given values, e = 1.6 10⁻¹⁹ C and f = 3 10^5 Hz : I = 1.6 10⁻¹⁹ 3 10^5 = 4.8 10⁻¹⁴ A The magnetic field B at the centre of the circular path is: B = ₀ I 2r Substituting ₀ = 4 10⁻⁷ T m/A and r = 0.5 10⁻¹⁰ m : B = 4 10⁻⁷ 4.8 10⁻¹⁴ 2 0.5 10⁻¹⁰ B = 19.2 10⁻²¹ 10⁻¹⁰ B = 19.2 10⁻¹¹ T B 60.3 10⁻¹¹ T 6.0 10⁻¹⁰ T