Solar Radiation and Energy

All the above given statements are perfectly correct. Use of a series of mirrors is indispensable for harnessing solar power. Solar energy can be tapped for generating electricity, heating homes, providing hot water, etc. Wind mills have been used by man for grinding food grains. Geothermal energy can be used for generation of electricity.

27 units are reflected by clouds.

The sun's energy is available in diffused form and there is no proper method to store this energy.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar technologies are employed to convert solar energy into another more useful form of energy. This would normally be a conversion to heat or electrical energy.

In a cell energy is stored in the form of chemical energy because cell consists of some chemicals, when these chemicals reacted then energy is released.

A vibrating body possesses sound energy, which is sensed by our ears.

Solar cells convert light energy into electric energy.

Ten percent law relates to the transfer of energy in successive trophic levels.

Sunflower turns towards sunlight to make food.

The Sun generates energy through nuclear fusion, where hydrogen nuclei combine to form helium in its core. This process releases enormous energy. Nuclear fission occurs in artificial reactors on Earth.

The Sun is primarily composed of Hydrogen (about 73% by mass) and Helium (about 25% by mass), with trace amounts of heavier elements. These elements undergo nuclear fusion in the Sun's core, producing the enormous energy that radiates outward.

Solar cooker is used to cook food on a sunny day because it requires a temperature of about 100^o C to 140^oC. Hence, option (2) is correct.

A solar flare is a phenomenon where the sun suddenly releases a great amount of solar radiation, much more than normal.

A photocell works on the photoelectric effect: when light photons strike a photosensitive material (like selenium or silicon), they eject electrons from the surface. These ejected electrons create an electric current, directly converting light energy into electrical energy without any intermediate steps. This principle is used in solar cells, light meters, and automatic lighting systems.

Greenhouses use infrared radiation from the Sun to warm plants and soil. The glass allows visible light to pass through, which is absorbed by plants and converted to heat. This heat is then re-radiated as infrared radiation, which glass traps effectively. Microwaves and gamma rays are not significant for greenhouse warming.