A glass plate 0.9cm thick has a reflective index of 1.50. how long does it take for a pulse of light to pass through the plate?


[c = 3.0 x 8 ms-1]

I. Total internal reflection of light.
II. Conservation of light energy.
III. Relative motion of the earth, sun and moon.
IV. Rectilinear propagation of light.
which of the above is a phenomenon of total solar eclipse?

I. Moon.
II. Sun.
III.street light.
IV. stars.
Which of these are natural sources of light?

An object is placed 5 cm from the pole of a concave mirror. if the focal length of the mirror is 10 cm. what is the image distance?

An object 4 cm high is placed 15 cm from a concave mirror of focal length 5 cm. The size of the image is?