Question

The resolving power of a telescope whose lens has a diameter of $1.22m$ for a wavelength of $5000\mathring{A}$ is:

• A. $2\times {10}^5$
• B. $2\times {10}^6$
• C. $2\times {10}^2$
• D. $2\times {10}^4$

Answer 1

The correct option is B $2\times {10}^6$

Resolving power$=\frac{d}{1.22\lambda }$
$=\frac{1.22}{1.22\times 5000\times {10}^{-10}}$
$=2\times {10}^6$