An electron is moving in Bohr's fourth orbit. Its de-Broglie wave length is . What is the circumference of the fourth orbit?

Step-by-step solution

According to Bohr's concept, an electron always move in the orbit with angular momentum ( m v r) equal to n h / 2 . m v r= n h 2 or r= n 2 ( h m v ) or r= n 2 (From de -Broglie equation, = h m v ) for fourth orbit n=4 gathered r= 2 circumference =2 r=2 2 =4 gathered