Solar Radiation and Energy

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.

Geothermal energy is not influenced by the sun. The source of geothermal energy is the heat present in the earth's crust.

Green house is a glass structure used to protect the plants from cold as it is a property of glass. Hence, option (3) is correct.

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.

Water's high specific heat means it can absorb large amounts of heat energy with minimal temperature change, making it ideal for thermal regulation in plants. Combined with its ready availability, this makes it perfect for dissipating excess solar energy.

A photocell (photoelectric cell) works on the photoelectric effect: when light strikes certain materials, it ejects electrons, creating an electric current. Thus light energy is directly converted into electrical energy without any intermediate steps.

Sun rays reach Earth through radiation - the transfer of energy through electromagnetic waves across the vacuum of space. Conduction and convection require a medium (solid, liquid, or gas), which doesn't exist in the vacuum between the Sun and Earth. Diffusion is not relevant to solar energy transfer.

Multiple energy sources drove the chemical reactions that led to life's origin. UV radiation from the sun, lightning discharges (electric charge), and geothermal heat (high temperature) all provided the energy needed to synthesize complex organic molecules from simpler inorganic compounds, as demonstrated by the Miller-Urey experiment.

The Sun is primarily composed of hydrogen (about 73% by mass) and helium (about 25% by mass), with trace amounts of heavier elements. These gases undergo nuclear fusion in the Sun's core, producing enormous energy. Note: the Sun 'burns' through nuclear fusion, not chemical burning.

Global dimming is the gradual reduction in the amount of global direct irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in the 1950s. The effect varies by location, but worldwide it has been estimated to be of the order of a 4% reduction over the three decades from 1960–1990.

A solar cell (also called a photovoltaic cell) is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect.