Question

The de-Broglie wavelength of an electron in the first Bohr orbit of circumference $2\pi r$ is

• A. $2\pi r$
• B. $\pi r$
• C. $\frac{1}{2}\pi r$
• D. $\frac{1}{4}\pi r$

Answer 1

The correct option is A $2\pi r$

According to Bohr's theory $mvr=n\frac{h}{2\pi }\Rightarrow 2\pi r=n\left(\frac{h}{mv}\right)=n\lambda$