In a compound microscope the objective and eye-piece have focal lengths of 0.95 cm and 5 cm respectively, and are kept at a distance of 20 cm. The last image is formed at a distance of 25 cm from eye-piece. What is the total magnification of the microscope?       


Correct option is



For eye-piece   


But length of the microscope is



Total magnification 



A parallel beam of white light falls on a convex lens. Images of blue, yellow and red light are formed on the other side of the lens at a distance of 20 cm, 20.5 cm and 21.4 cm respectively. The dispersive power of the material of the lens will be: 



A thin prism made of glass is dipped in water; then minimum deviation with respect to air by it will be:



A prism has a refracting angle 60o. A ray of given monochromatic light suffers minimum deviation of 38o in passing through the prism. The refractive index of the material of the prism is:


A liquid is placed in a hollow prism of angle 60o. If angle of minimum deviation is 30o, what is the refractive index of the liquid?     


We have a right-angled isosceles prism. Its refracting index is 1.5. If a ray is incident normally on one of the two perpendicular surfaces which of the following phenomena will take place?    


A beam of light consisting of red, green and blue colours is incident on a right-angled prism. The refractive indices of the material of the prism for the above red, green and blue wavelengths are 1.39, 1.44 and 1.47 respectively. The prism will:


If the ratio of magnifications produced by a simple microscope in near point adjustment and far point adjustment is 6/5, then the focal length of the lens is (take D = 25 cm):    


When the length of a microscope increases its magnifying power:


The focal length of the objective and the eyepiece of a compound microscope are 1 cm and 5 cm respectively. An object is placed at a distance of 1.1 cm from the objective. If the final image is formed at the least distance of distinct vision, the magnifying power is:        


A person cannot see objects clearly beyond 50 cm. The power of the lens to correct the vision is: