Question

The diameter of the lens of a telescope is $0.61 \, m$ and the wavelength of light used is $5000 \, \text{Å}$ . The resolution power of the telescope is

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

Answer 1

Answer: (B)

Resolving power $\left(\frac{1}{d \theta }\right)=\frac{D}{1.22 \lambda }$
$=\frac{0.61}{1.22 \times 5000 \times 10^{- 10}}$
$=10^{6}$