Stars twinkle because
A). the intensity of light emitted by them changes with time.
B). the refractive index of the different layers of the earth's atmosphere changes continuously.
C). the refractive index of the different layers of the earth's atmosphere changes continuously.
D). None of these
the refractive index of the different layers of the earth's atmosphere changes continuously.
Stars twinkle because the refractive index of the different layers of the earth's atmosphere changes continuously.
1. The time period of a seconds pendulum Is
2. . . . . . . . . . exerts a force on anything that has an electric charge.
3. Increased wind speed is accompanied by a reduced air ________
5. The land mass of India has an area of ______ million square km.
7. Lakes freeze in cold countries in winter, leaving the water underneath at
8. Conversion of heat into electrical is achieved by using :