Whatis theminimumangularseparation between two stars if a telescope is used to observe them, with an objective of aperture 20 cms. (`lambda = 5900 overset@A`)

What is the minimum distance between two objects which can be resolved by a microscope having the visual angle of 30^@ when light of wavelength 500 nm is used ?

What happens to the gravitational force between two objects when the distance between them is: (i) doubled? (ii) halved?

A telescope has an objective of diameter 2.5 m. What is the angular resolution, When it observes at 5500 overset@A .

A telescope using an eye piece of focal length 3 cm has a magnification 10 in normal adjustment. If the telescope is now used to view an object placed at a distance of 180 cm from the objective, the new length of the telescope is (assume final image is at infinity).

The semivertical angle of a cone of the rays incident on the objective of the microscope is 20^@ . If lambda = 6600 overset@A , calculate the smallest distance between two points which can be just resolved.

In a single slit diffraction pattern, the distance between the 1st minima on the right and the 1st minima on the left is 5.2 mm. The screen on which the pattern is displayed is 80 cm from the slit. If lambda= 5460 overset@A . Calculate the slit width.

A telescope using an eye piece of focal length 2 cm has a magnification 20 in normal adjustment. If the telescope is now used to view an object placed at a distance of 2 m from the objective, the new length of the telescope is (assume final image is at infinity).

For the same objective ,find the ratio of the least separation between two points to be distinguished by a microscope for light of 5000 overset (@)(A) and electrons accelerated through 100 V used as the illuminating substance.

Whan a _____ is introduced between objective and eye piece of telescope then it can be used as a terrestrial telescope.