Diameter of the objective lens of a telescope is $250 \mathrm{~cm}$. For light of wavelength $600…

Diameter of the objective lens of a telescope is $250 \mathrm{~cm}$. For light of wavelength $600 \mathrm{~nm}$, coming from a distant object, the limit of resolution of the telescope is close to
  1. $1.5 \times 10^{-7} \mathrm{rad}$
  2. $2.0 \times 10^{-7} \mathrm{rad}$
  3. $3.0 \times 10^{-7} \mathrm{rad}$
  4. $4.5 \times 10^{-7} \mathrm{rad}$

Solution

$\begin{aligned} & \text { Limit of resolution }=\frac{1.22 \lambda}{d} \\ & =\frac{1.22 \times 600 \times 10^{-9}}{250 \times 10^{-2}}=3 \times 10^{-7} \mathrm{rad}\end{aligned}$

Asked in: AP EAMCET 2023 (17 May Shift 2)

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