Question Text
Question 3 :
Light moves from air into water. The light makes an angle of $47^{\circ}$ with the normal in the air. What angle will it make with the normal in the water?<br>The index of refraction for air is $1.00$.<br>The index of refraction for water is $1.33$
Question 6 :
The focal length of a lens can be expressed in :
Question 8 :
A straight line passing through the two centres of curvature of lens is called
Question 9 :
When a drop of oil is spread on a water surface, it displays beautiful colours in daylight because of :
Question 11 :
A real image, equal in size to the object, is obtained when the object is placed at the centre of curvature in front of which mirror?
Question 12 :
On the basis of their experiment, "To trace the path of a ray of light through a rectangular glass slab," students of a class arrived at which one of the following conclusions :
Question 14 :
A real, inverted and equal in size image is formed by
Question 15 :
What is the angle of incidence when a ray of light incident on a concave mirror from its centre of curvature?
Question 16 :
Fill in the blanks:Principal axis is also called ________ of the lens.
Question 17 :
How does the power of a lens change if its focal length is doubled?<br>
Question 18 :
If in a plano-convex lens, the radius of curvature of the convex surface is 10 cm and the focal length of the lens is 30 cm, then the refractive index of the material of lens will be
Question 19 :
Convex lens are used in eyeglasses to correct which type of defect?<br>