A simple microscope using a single lens often shows coloured image of a white source. Why?

Why clouds are seen to be of white colour ?

What is simple microscope ? Obtain the equation of magnification for the image formed at normal vision distance.

Answer the following questions: (c) Magnifying power of a simple microscope is inversely proportional to the focal length of the lens. What then stops us from using a convex lens of smaller and smaller focal length and achieving greater and greater magnifying power?

A compound microscope consists of an objective lens of focal length 2.0 cm and an eyepiece of focal length 6.25 cm separated by a distance of 15cm. How far from the objective should an object be placed in order to obtain the final image at (a) the least distance of distinct vision (25cm), and (b) at infinity? What is the magnifying power of the microscope in each case?

To check the pH of tap water and compare it with pH of the water in the local water body. Apparatus : Test tubes or beaker Materials : Universal pH indicator / litmus paper Procedure : implies Take water sample from tap of your home in a test tube. implies Add few drops of the universal indicator into the test tube containing tap water. implies Observe the water sample in the test tube for colour change. implies Test pH using a litmus paper, in the water sample placed in a beaker. implies Dip the litmus paper into the water in the local water body. implies Observe colour changes of the litmus paper. Observation : implies Test tube containing tap water, turns yellow colour with addition of pH indicator. implies Litmus paper does not show colour change with tap water. implies Water sample collected from pond shows red colour with pH indicator. Litmus paper turns red as it is dipped in water of local water body. Conclusion : The uncontaminated tap water is neutral while water of local water body is acidic. Can you say whether the water is polluted or not on the basis of your observations?

To check the pH of tap water and compare it with pH of the water in the local water body. Apparatus : Test tubes or beaker Materials : Universal pH indicator / litmus paper Procedure : implies Take water sample from tap of your home in a test tube. implies Add few drops of the universal indicator into the test tube containing tap water. implies Observe the water sample in the test tube for colour change. implies Test pH using a litmus paper, in the water sample placed in a beaker. implies Dip the litmus paper into the water in the local water body. implies Observe colour changes of the litmus paper. Observation : implies Test tube containing tap water, turns yellow colour with addition of pH indicator. implies Litmus paper does not show colour change with tap water. implies Water sample collected from pond shows red colour with pH indicator. Litmus paper turns red as it is dipped in water of local water body. Conclusion : The uncontaminated tap water is neutral while water of local water body is acidic. What is the cause for acidic water in water body?

To check the pH of tap water and compare it with pH of the water in the local water body. Apparatus : Test tubes or beaker Materials : Universal pH indicator / litmus paper Procedure : implies Take water sample from tap of your home in a test tube. implies Add few drops of the universal indicator into the test tube containing tap water. implies Observe the water sample in the test tube for colour change. implies Test pH using a litmus paper, in the water sample placed in a beaker. implies Dip the litmus paper into the water in the local water body. implies Observe colour changes of the litmus paper. Observation : implies Test tube containing tap water, turns yellow colour with addition of pH indicator. implies Litmus paper does not show colour change with tap water. implies Water sample collected from pond shows red colour with pH indicator. Litmus paper turns red as it is dipped in water of local water body. Conclusion : The uncontaminated tap water is neutral while water of local water body is acidic. Can aquatic life survive in acidic water of water body?

A thin convex lens of focal length 5 cm is used as a simple microscope by a person with normal near point (25"cm") . What is the magnifying power of the microscope.?

A convex lens of focal length 12.5 cm is used as a simple microscope. When the image is formed at infinite, Magnification is ....... (Near point for the normal vision is 25 cm).