Energy

Abstract

Human is one of the most important living organisms on the planet earth which looks after other living organism including wildlife to sustain nature. They need clean air, water and organic food for longer life. Energy is fourth basic need of human after air, water and food.

Appendices

Problems

Problem 1.1

Evaluate an average wavelength radiation emitted from surface at temperature of 100 $^\circ{\rm C}$ and 200 $\mathrm{^\circ{\rm C} }$.

Hint: See Example 1.1

Problem 1.2

Evaluate an extra-terrestrial solar radiation on February, 29 and June 22, 2022 (leap year) for solar constant of $1367\mathrm{ W}/{\mathrm{m}}^{2}$

Hint: See Example 1.2

Problem 1.3

Calculate total radiation from the Sun for given radius (R) of $12.75\times {10}^{6}\mathrm{m}$ and temperature of 6000 K.

Hint: See Example 1.4

Problem 1.4

Find out the energy associated with one photon having frequency of 0.3 and 3 $\mathrm{\mu m}$

Hint: See Example 1.5

Problem 1.5

Calculate $E=m{c}^{2}$ for fusion taking place inside Sun.

Hint: See Eq. (1.1)

Problem 1.6

Plot the curve between energy (E) and $\lambda$ which is varying between 0.3 and 3 $\mathrm{\mu m}$ (visible wavelength).

Hint: See Example 1.5

Problem 1.7

Plot the curve between frequency ($\nu$) and $\lambda$ which is varying between 0.3 and 3 $\mathrm{\mu m}$

Hint: See Example 1.5

Problem 1.8

Plot the curve between wavelength ($\lambda )$ in hertz and frequency ($\nu$) in $\mathrm{\mu m}$ which is varying between 0.3 and 3 $\mathrm{\mu m} \left[1 \mathrm{\mu m}=2.997\times {10}^{14 }\mathrm{Hz}\right]$ and $\lambda$ which is varying between 3 and 0.3

Hint: See Example 1.5

Problem 1.9

Plot the variation of $\mathrm{effective \, emissivity \, of \, the \, Earth }(\epsilon$) with respect to CO₂ concentration vary from 280 to 420 ppm.

Hint: See Example 1.7

Problem 1.10

Plot global average atmospheric air temperature with varying $\mathrm{effective \, emissivity \, of \, the \, Earth }(\epsilon$).

Hint: See Example 1.7 and 1.8.

Objective Questions

1.1 The wavelength radiation emitted from surface is

• (a) Proportional to temperature

• (b) Inversely proportional to temperature

• (c) Equal to temperature

• (d) None of them

Answer: (b).

1.2 Solar constant is measured in/on

• (a) Surface of earth

• (b) Terrestrial region

• (c) Extraterrestrial region

• (d) The surface of Sun

Answer: (c).

1.3 The maximum radiation is emitted by

• (a) The surface of sea

• (b) The surface of Earth

• (c) The surface of rock

• (d) The surface of Sun

Answer: (d).

1.4 The sun emits

• (a) Short wavelength radiation

• (b) Long wavelength radiation

• (c) Zero wavelength radiation

• (d) None of them

Answer: (a).

1.5 The Earth emits

• (a) Short wavelength radiation

• (b) Long wavelength radiation

• (c) Zero wavelength radiation

• (d) None of them

Answer: (b).

1.6 Atmospheric gases with respect to air are

• (a) Zero weight

• (b) Heavy weight

• (c) Light weight

• (d) None of above

Answer: (c).

1.7 Ozone (O₃) layer is disrupted by

• (a) Satellite

• (b) Aero plane

• (c) Dust

• (d) All of them

Answer: (a).

1.8 Frequency ($\nu$) is

• (a) Inversely proportional to wavelength ($\lambda )$

• (b) Proportional to wavelength ($\lambda )$

• (c) Equal to wavelength ($\lambda )$

• (d) None of them

Answer: (a)

1.9 Wavelengths ($\lambda )$ is

• (a) Inversely proportional to frequency ($\nu$)

• (b) Proportional to frequency ($\nu$)

• (c) Equal to frequency .

• (d) None of them

Answer: (a)

1.10 Energy emitted by surface of Sun at 6000 K is

• (a) Higher than energy generated at core of Sun

• (b) Lower than energy generated at core of Sun

• (c) Equal to energy generated at core of Sun

• (d) None of them

Answer: (b).

1.11 The main greenhouse gases of atmosphere (stratosphere) are

• (a) Nitrogen (N₂), oxygen (O₂)

• (b) Argon, carbon dioxide (CO₂)

• (c) Trace gases namely vapor, ozone(O₃),, methane, various oxides of nitrogen, neon, and Helium (He)

• (d) All of them

Answer: (d).

1.12 The algae is formed with interaction of photon

• (a) Water molecule of free moving water surface

• (b) Water molecule of free stagnant water surface

• (c) Water content in the plant

• (d) All of them

Answer: (b) and (c).

1.13 The $\mathrm{effective\, emissivity\, of\, the\, Earth\, }(\epsilon$) will increase

• (a) With increase of CO₂ concentration

• (b) With decrease of CO₂ concentration

• (c) With no effect of CO₂ concentration

• (d) None of them

Answer: (b).

1.14 The $\mathrm{effective\, emissivity\, of\, the\, Earth\, }(\epsilon$) will decrease

• (a) With increase of CO₂ concentration

• (b) With decrease of CO₂ concentration

• (c) With no effect of CO₂ concentration

• (d) None of them

Answer: (a).

1.15 The global average atmospheric air temperature will increase

• (a) With increase of CO₂ concentration

• (b) With decrease of CO₂ concentration

• (c) With no effect of CO₂ concentration

• (d) None of them

Answer: (a).