Question

The orbital speed of an electron orbiting around a nucleus in a circular orbit of radius 50 pm is 2.2 × 10⁶ ms⁻¹. Then the magnetic dipole moment of an electron is:

Options

• 1.6 × 10⁻¹⁹ Am²

• 5.3 × 10⁻²¹ Am²

• 8.8 × 10⁻²⁵ Am²

• 8.8 × 10⁻²⁶ Am²

Answer 1

8.8 × 10⁻²⁵ Am²

Explanation:

Magnetic dipole moment

m = iA = `"e"/"T" xx π"r"^2 = "e"/((2π"r"//"v")) xx π"r"^2 = "erv"/2`

= `(1.6 xx 10^-19 xx 50 xx 10^-12 xx 2.2 xx 10^6)/2`

= 8.8 × 10⁻²⁵ Am²