What is the shape of the wavefront in each of the following cases: Light emerging out of a convex lens when a point source is placed at its focus.

What is the shape of the wavefront in each of the following cases:Light diverging from a point source.

What is the shape of the wavefront in each of the following cases: The portion of the wavefront of light from a distant star intercepted by the Earth.

What is the geometrical shape of the wavefront when a plane passes through a convex lens?

What type of wavefront will emerge from a point source?

Find the standard equation of hyperbola in each of the following cases: (i) Distance between the foci of hyperbola is 16 and its eccentricity is sqrt2. (ii) Vertices of hyperbola are (pm4,0) and foci of hyperbola are (pm6,0) . (iii) Foci of hyperbola are (0,pmsqrt(10)) and it passes through the point (2,3). (iv) Distance of one of the vertices of hyperbola from the foci are 3 and 1.

What changes in the focal length of a convex lens occur,when the incident violet light on them is replaced by red light?

In these question, a statement of asertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion:If a convex lens is kept in water,its convergent power decreses. Reason:Focal length of convex lens in water increases.

In these question, a statement of asertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion:Position of image approches focus of a lens,only when object approaches infinity. Reason:Paraxial rays inident parallel to principal axis intersect at the focus after refraction from the lens.

In these question, a statement of assertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion: A concave and convex lens both have the same focal length in air. When they both have the same focal length in air. When they are submerged in water they will have the same focal length. Reason: The refractive index of water is smaller than the refractive index of air.