Solar Radiation and Energy

Radiative zone lies between the core and the convective zone. In radiative zone, energy resulted from the nuclear fusion in the core travels upwards by photons.

Reason for enormous energy output of sun is the fusion reaction

Solar heat causes the evaporation of water from the surface of the leaves in form of water vapour through small openings called stomata. This loss is known as transpiration. Due to the loss of water, water stress condition is created that forces the upward movement of water from the soil towards the shoot system. This water is then again distributed to various plant parts.

The protonproton chain reaction is one of two known sets of nuclear fusion reactions by which stars convert hydrogen to helium. Using this method, the stars convert particles to energy

Sun is the ultimate source of energy. The radiation of sun helps to warm the earth. Changing the temperature of earth forms different season. Plants directly depend on the sun to prepare their own by photosynthesis. Sun provides energy in different form solar energy. Thus, the correct option is C.

Vitamin D is not one chemical but many. The natural type is produced in the skin from a universally present form of cholesterol, 7-dehydrocholesterol. Sunlight is the key: Its ultraviolet B (UVB) energy converts the precursor to vitamin D3. In contrast, most dietary supplements are manufactured by exposing a plant sterol to ultraviolet energy, thus producing vitamin D2. Because their function is almost identical, D2 and D3 are lumped together under the name vitamin D, but neither will function until the body works its magic. The sun’s energy turns a chemical in your skin into vitamin D3, which is carried to your liver and then your kidneys to transform it to active vitamin D. 

The sun's surface emits about 63 million watts of energy per square meter. By the time it reaches the Earth, after traveling 150 million kilometers, or 93 million miles, it has dimnished to 1,370 watts per square meter which are equal to thousand of kilocalories.

Energy source responsible for upward flow of water is solar heat. Due to increase in the solar heat the temperature increases. The rate of transpiration is high on a bright sunny day due to excessive heat produced by solar heat. The water is lost from guard cell which leads to decrease in the water potential of guard cell as compared to the surrounding cell. To stabilize the water potential in the guard cell water rushes from the neighboring cell which creates a cohesion pull in the xylem vessels to pull the water up to the guard cell. Thus, the rate of water absorption increases when the transpiration is high. 

Energy obtained by the Sun in form of heat and light is due to the nuclear reaction: fusion reaction taking place in the Sun. Hydrogen atoms collide to combine with each other to form a heavier molecule Helium, this results in release of a large amount of energy.

The Sun gives us heat and light energy.

Ultimate sorce of energy is the Sun. Living beings depend on the Sun for its sustainability. All other other sources of energy directly or indirectly are depended on the energy recieved by the Sun.

Solar energy is a renewable source of energy and is available abundantly and is free of cost. The other forms of energy such as wind energy, thermal energy, chemical energy obtained from plants, etc. are all obtained from Sun. hence sun is the ultimate source of energy as all energy chains start from it.

Sun is the source of almost all the energies in our Earth. Plants make food using sunlight, the food that we get from plants and animals also has its prime source as sunlight. The fossil fuels that we use in our daily life comes from dead plants and animals which again have their source as solar energy. The wind that blows is due to heat absorbed by the atmosphere from the sunlight.