In Fizeau method of measuring the speed of light, the toothed wheel is placed in the focal plane of a converging lens. How would the experiment be affected if the wheel is slightly away from the focal plane ?

A point source of light is placed at a distance of 2f from a converging lens of focal length f. The intensity on the other side of the lens is maximum at a distance

In producing a pure spectrum, the incident light is passed through a narrow slit placed in the focal plane of an chromatic lens because a narrow slit

Consider Galileo's method of measuring the speed of light using two lanterns. To get an accuracy of about 10%, the time taken by the experimenter in closing or opening the shutter should be about one tenth of the time taken by the light in going from one experimenter to the other. Assume that it takes 1/100 second for an experimenter to close or open the shutter. How far should the two experimenters be to get a 10% accuracy ? What are the difficulties in having this separation ?

A 5 cm high object is placed at a distance of 25 cm from a converging lens of focal length of 10 cm. Determine the position, size and type of the image.

An object of size 3.0 cm is placed 14 cm in front of a concave lens of focal length 21 cm. Describe the image produced by the lens. What happens if the object is moved further away from the lens ?

A beam of light converges at a point P. Nnw a lens is placed in the path of the convergent beam 12cm from P. At what point does the beam converge if the lens is (a) a convex lens of focal length 20 cm, and (b) a concave lens of focal length 16 cm ?

A beam of light converges to a point P , A lens is placed in the path of the convergent beams 12 cm from P. At what point does the beam converge if the lens is a. A convex lens of focal length 20 cm. b. A concave lens of focal length 16 cm ?

What is the effect on the interference fringes in a Young' double slit experiment due to each of the following operations. a. the screen is moved away from the plane of the slits. b. the (monolchromatic) source is replaced by another (monochromatic) source of shorter wavelength. c. the separation between the two slits is increased. d. the source slit is moved closer to the double slit plane: e. the width of the source slit is increased. f. The monochromatic source is replaced by a source of white light? (in each operation, take all parameters, other than the one specified, to remain unchanged).

Figure shows an equiconvex lens (of refractive index 1.50 ) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted image is found at the position of the needle. The distance of the needle from the lens is measured to be 45.0 cm. The liquid is removed and the experiment is repeated . the new distance is measured to be 30.0 cm. What is the refractive index of the liquid ?

In an experiment to measure the speed of light by Fizeau's apparatus, following data are used : Distance between the mirrors = 12.0 km, Number of teeth in the wheel = 180. Find the minimum angular speed of the wheel for which the image is not seen.