JEE Main2016PhysicsWave OpticsActual
Two stars are 10 light years away from the earth. They are seen through a telescope of objective diameter 30 cm. The wavelength of light is 600nm. To see the stars just resolved by the telescope, the minimum distance between them should be 1 l i g h t y e a r = 9.46 × 10 15 m of the order of :
Options
- A10 8 k m
- B10 10 k m
- C10 11 k m
- D10 6 k m
Correct answer
A. 10 8 k m
Step-by-step solution
l = R a 1 . 22 × λ and a = 30  c m ⇒ l = 9.46 × 10 15 × 10 × 1 . 22 × 600 × 10 - 9 0 . 3 = 2.30 × 10 11 m ⇒       2.30 × 10 8   k m