Question

For the Bohr's first orbit of circumference $2\pi r$, the de-Broglie wavelength of revolcing electron will be.

• 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 $2\pi r$

$mvr=\frac{nh}{2\pi }$, according to Bohr's theory
$\Rightarrow 2\pi r=n\left(\frac{h}{mv}\right)=n\lambda$ for $n=1,\lambda =2\pi r$