The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 Å is of the order of (a) 106 rad (b) 10 - 2 rad (c) 10 - 4 rad (d) 10 - 6 rad.

Answer: (d). θ = (1.22λ)/(D) with λ = 5×10⁻⁷ m, D = 0.1 m. θ = 1.22×5×10⁻⁷0.1 = 6.1×10⁻⁶ rad So the answer is (d) of the order of 10⁻⁶ rad.

The angular resolution of a 10 cm diameter telescope at a wavelength… | NEET 2005 (AIPMT)

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The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 $\text{Å}$ is of the order of

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Answer: (d)

$\theta = \dfrac{1.22\lambda}{D}$ with $\lambda = 5\times10^{-7}$ m, $D = 0.1$ m.
$\theta = \dfrac{1.22\times5\times10^{-7}}{0.1} = 6.1\times10^{-6}$ rad
So the answer is (d) of the order of $10^{-6}$ rad.