Question

The diameter of the lens of a telescope is 1.22 m., the wavelength of light is $5000A^0$ the resolution power of the telescope 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 $2\times {10}^6$

Given, diameter of the lens of a telescope, $d=1.22m$, and wavelength of light, $\lambda =5000A^{\circ }=5000\times {10}^{-10}m$.

We know, resolution power of a telescope is,

$r.p.=\frac{d}{1.22\lambda }$

$\therefore r.p.=\frac{1.22}{1.22\times 5000\times {10}^{-10}}=2\times {10}^6$

So, the correct answer is - (B) $2\times {10}^6$