Some distant star is to be observed by some telescope of diameter of objective lens , at an angular resolution

Question

Some distant star is to be observed by some telescope of diameter of objective lens $a$ , at an angular resolution of $3.0 \times 10^{- 7}$ radian. If the wavelength of light from the star reaching the telescope is 500 nm, the minimum diameter of the objective lens of the telescope is ______ cm. (nearest integer) [2026]

Smart Achievers · Accepted Answer

(203)

$θ = \frac{1.22 λ}{b}$

$3 \times 10^{- 7} = \frac{1.22 \times 5 \times 10^{- 7}}{b}$

$\Rightarrow b = 203.33 cm$

Solution

Ans.
(203)

$θ = \frac{1.22 λ}{b}$

$3 \times 10^{- 7} = \frac{1.22 \times 5 \times 10^{- 7}}{b}$

$\Rightarrow b = 203.33 cm$

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Solution

Ans. (203) θ=1.22λb 3×10-7=1.22×5×10-7b ⇒b=203.33 cm

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Ans.
(203)

$θ = \frac{1.22 λ}{b}$

$3 \times 10^{- 7} = \frac{1.22 \times 5 \times 10^{- 7}}{b}$

$\Rightarrow b = 203.33 cm$