When we enter some dark room then for some time we are not able to see anything and rKHOaning there for long,if suddenly strong light is switched on then our eyes can not see anything why?

Why does a person not able to see for some time when he comes out of a well lighted room at night or enters a dark room at day time?

These questions consist of two statements each,printed as Assertion and Reason.While answering these questions you are required to chose any one of the following four responses. If both Assertion and Reason are true and Reason in correct explanation of Assertion. If both assertion and Reason are true but reason is not correct explanation of Assertion. If Assertion is true but Reason is false. If both Assertion and Reason are false. Assertion:A man is blind for some time when he comes out of a well lighted room to a dark place. Reason:iodopsin of cone cells is bleached in the presence of strong light.

Answer the following questions: A virtual image, we always say, cannot be caught on a screen. Yet when we ‘see’ a virtual image, we are obviously bringing it on to the ‘screen’ (i.e. the retina) of our eye. Is there a contradiction?

Why does our palm feel cold when we put some acetone or petrol or perfume on it?

How many galaxies are present in the universe? Do all the stars that we can see with naked eye belong to our galaxy? Does earth is a part of solar system?

Diffraction of light Diffraction of light is the phenomenon of bending of light round corners of an obstacle or aperture and spreading into the geometrical shadow of the diffracting object. The condition for diffraction of light is the size of the aperture should be comparable to the wavelength of incident light. so in daily life, we find that diffraction of sound is more common than the diffraction of light. width of central maxima is {formula= ((2lambdaD)/d) } Two student are separated by a 5 m partition wall in a room that is 10 m high. if both light and sound waves bend around obstacles, we find that the students are unable to see the each other even though they can converse easily. it is due to

Classically, an electron can be in any orbit around the nucleus of an atom. Then what determines the typical atomic size? Why is an atom not, say, thousand times bigger than its typical size? The question had greatly puzzled Bohr before he arrived at his famous model of the atom that you have learnt in the text. To simulate what he might well have done before his discovery, let us play as follows with the basic constants of and see if we can get a quantity with the dimensions of length that is roughly equal to the known of an atom (~ 10^ -10 m).- Construct a quantity with the dimensions of length from the fundamental constants e, m_e , and c. Determine its numerical value.