An electron is revolving in an orbit of radius 2 A with a speed of 4

1.	An electron is revolving in an orbit of radius 2 A with a speed of 4 x 105 m /s. The angular momentum of the electron is [Me = 9 x 10-31 kg](a) 2 x 10-35 kg m2 s-1 (b) 72 x 10-36 kg m2 s-1 (c) 7.2 x 10-34 kg m2 s-1 (d) 0.72 x 10-37 kg m2 s-1
Answer» (b) Angular momentum L = mV x r = 9 x 10^-31 x 4 x 10⁵ x 2 x 10^-10 = 72 x 10^-36 kg m² s^-1

An electron is revolving in an orbit of radius 2 A with a speed of 4 x 105 m /s. The angular momentum of the electron is [Me = 9 x 10-31 kg](a) 2 x 10-35 kg m2 s-1 (b) 72 x 10-36 kg m2 s-1 (c) 7.2 x 10-34 kg m2 s-1 (d) 0.72 x 10-37 kg m2 s-1

Answer»

(b) Angular momentum

L = mV x r

= 9 x 10^-31 x 4 x 10⁵ x 2 x 10^-10

= 72 x 10^-36 kg m² s^-1