How can the resolving power of a telescope be increased ?

Calculate the resolving power of a telescope whose limit of resolution is 2.44xx10^(-6) rad.

Diameter of the objective of a telescope is 200 cm. What is the resolving power of a telescope ? Take wavelength of light =5000 Å .

An electron microscope uses electrons accelerated by a voltage of 50 kV. Determine the de-Broglie wavelength associated with the electrons. Taking other factors, such as numerical aperture etc. to be same, how does the resolving power of an electron microscope compare with that of an optical microscope which uses yellow light?

A telescope of aperture 0.02 m is used to focus the two head lamps 1.2m apart. If the wavelength of light emitted by the automobile is 589.6 nm then calculate the resolving power of the telescope. If the R.P of the eye is 3.436xx10^3 "rad"^(-1) , then calculate the magnifying power of the telescope.

In order to raise the resolving power of the electron microscope we should :

Can power of a lens be negative?

To increase magnifying power of a telescope, we should increase