The focal lengths of the objective and the eye piece of an astronomical telescope are 100 cm and 5 cm respectively. Calculate its magnifying power.

The focal lenghts of objectives and eyepiece of a telescope are 200cm and 10 cm respectively. Is is used to get an image of the Sun on a screen placed 40cm behind the eyepiece. The diameter of the image is 6cm. What is the diameter of the Sun? Give the distance from earth to the Sun is 1.5xx10^(11)m .

The objective lens and eye piece lens of a Compound microscope have focal length 1.5cm and 5 cm respectively. The object is placed at a distance 1.8 cm. What is its magnification?