General Knowledge Questions

Mixed economy is the most common economic system in the world.

Venus has a very high surface temperature of 500o Cand the pressure is 90 times that on the earth.

No. Boiling water is not a chemical change. Because in this process it doesn't loss its properties. It just changes its state i.e, from liquid state to gaseous.

Hence, Boiling water is a Physiacl change and not a chemical change.

Incapable of being seen through is Opaque in nature.

Cobalt therapy or cobalt-60 therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer.

Cobalt 60 is a synthetic radioactive isotope of cobalt with a half-life of 5.2714 years. It is produced artificially in nuclear reactors.

According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.Therefore, light other than red is mostly scattered away. Most of the red light, which is the least scattered, enters our eyes. Hence, the sun and the sky appear red.