Questions

In order of increasing penetration power, alpha particles have the lowest, then beta particles, then gamma rays.

According to wave theories, for Total internal reflection tohappen: Light must travel from denser medium to rarer medium. Angle of incidence should be greater than critical angle. As in case of TIR, the image is perfectly clear, it implies that there has been no loss of intensity.

Presently, there are 226 flood forecasting stations consisting of 166 level forecasting stations for villages and towns and 60 inflow forecasting stations for reservoirs/dams/barrages in the country. Existing flood forecasting network covers 22 States / Union Territories and 19 major river basins / sub-basins in the country.

On December 21, the earth is in an equivalent position on the opposite points in its orbit, So the South pole is tipped towards the sun and North pole away from it resulting in 24 hours of darkness at the North pole, as the sun is overhead on the Tropic of Capricorn. This phenomenon is winter solstice; while on June 21, North pole is tipped towards the Sun but the South pole is tipped away from the sun resulting in 24 hours of darkness on the South Pole, as the sun is overhead on the Tropic of Cancer.This phenomenon is summer solstice; while Aphelion is the position of the earth in its orbit when it is at its distant point from the sun.