B.2 Greenhouse effect

Estimate, in °C, the temperature of the roof tiles.

Estimate, in °C, the temperature of the roof tiles.

Estimate, in °C, the temperature of the roof tiles.

A black body is on the Moon’s surface at point A. Show that the maximum temperature that this body can reach is 400 K. Assume that the Earth and the Moon are the same distance from the Sun.

A black body is on the Moon’s surface at point A. Show that the maximum temperature that this body can reach is 400 K. Assume that the Earth and the Moon are the same distance from the Sun.

A black body is on the Moon’s surface at point A. Show that the maximum temperature that this body can reach is 400 K. Assume that the Earth and the Moon are the same distance from the Sun.

The albedo of the Earth’s atmosphere is 0.28. Outline why the maximum temperature of a black body on the Earth when the Sun is overhead is less than that at point A on the Moon.

The albedo of the Earth’s atmosphere is 0.28. Outline why the maximum temperature of a black body on the Earth when the Sun is overhead is less than that at point A on the Moon.

The albedo of the Earth’s atmosphere is 0.28. Outline why the maximum temperature of a black body on the Earth when the Sun is overhead is less than that at point A on the Moon.

The average temperature of the surface of a planet is five times greater than the average temperature of the surface of its moon. The emissivities of the planet and the moon are the same. The average intensity radiated by the planet is $I$. What is the average intensity radiated by its moon?

A.  $\frac{I}{25}$

B.  $\frac{I}{125}$

C.  $\frac{I}{625}$

D.  $\frac{I}{3125}$

The average temperature of the surface of a planet is five times greater than the average temperature of the surface of its moon. The emissivities of the planet and the moon are the same. The average intensity radiated by the planet is $I$. What is the average intensity radiated by its moon?

A.  $\frac{I}{25}$

B.  $\frac{I}{125}$

C.  $\frac{I}{625}$

D.  $\frac{I}{3125}$

A black body at temperature T emits radiation with peak wavelength ${\lambda }_{\text{ρ}}$ and power P. What is the temperature of the black body and the power emitted for a peak wavelength of $\frac{{\lambda }_{\text{ρ}}}{2}$?

A black body at temperature T emits radiation with peak wavelength ${\lambda }_{\text{ρ}}$ and power P. What is the temperature of the black body and the power emitted for a peak wavelength of $\frac{{\lambda }_{\text{ρ}}}{2}$?

Show that the intensity of the solar radiation at the location of Titan is 16 W m⁻²

Show that the intensity of the solar radiation at the location of Titan is 16 W m⁻²

Show that the intensity of the solar radiation at the location of Titan is 16 W m⁻²

Titan has an atmosphere of nitrogen. The albedo of the atmosphere is 0.22. The surface of Titan may be assumed to be a black body. Explain why the average intensity of solar radiation absorbed by the whole surface of Titan is 3.1 W m⁻²

Titan has an atmosphere of nitrogen. The albedo of the atmosphere is 0.22. The surface of Titan may be assumed to be a black body. Explain why the average intensity of solar radiation absorbed by the whole surface of Titan is 3.1 W m⁻²

Titan has an atmosphere of nitrogen. The albedo of the atmosphere is 0.22. The surface of Titan may be assumed to be a black body. Explain why the average intensity of solar radiation absorbed by the whole surface of Titan is 3.1 W m⁻²

The diagram shows, for a region on the Earth’s surface, the incident, radiated and reflected intensities of the solar radiation.

What is the albedo of the region?

A.  $\frac{1}{4}$

B.  $\frac{1}{3}$

C.  $\frac{3}{4}$

D.  $1$

The diagram shows, for a region on the Earth’s surface, the incident, radiated and reflected intensities of the solar radiation.

What is the albedo of the region?

A.  $\frac{1}{4}$

B.  $\frac{1}{3}$

C.  $\frac{3}{4}$

D.  $1$

The missing section of insulation is 0.56 m long and the external radius of the pipe is 0.067 m. The emissivity of the pipe surface is 0.40. Determine the energy lost every second from the pipe surface. Ignore any absorption of radiation by the pipe surface.

The missing section of insulation is 0.56 m long and the external radius of the pipe is 0.067 m. The emissivity of the pipe surface is 0.40. Determine the energy lost every second from the pipe surface. Ignore any absorption of radiation by the pipe surface.

The missing section of insulation is 0.56 m long and the external radius of the pipe is 0.067 m. The emissivity of the pipe surface is 0.40. Determine the energy lost every second from the pipe surface. Ignore any absorption of radiation by the pipe surface.

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Two surfaces X and Y emit radiation of the same surface intensity. X emits a radiation of peak wavelength twice that of Y.

What is $\frac{\mathrm{emissivity} \mathrm{of} \mathrm{X}}{\mathrm{emissivity} \mathrm{of} \mathrm{Y}}$?

A.  $\frac{1}{16}$

B.  $\frac{1}{2}$

C.  2

D.  16

Light of intensity 500 W m⁻² is incident on concrete and on snow. 300 W m⁻² is reflected from the
concrete and 400 W m⁻² is reflected from the snow.

What is $\frac{\mathrm{albedo} \mathrm{of} \mathrm{concrete}}{\mathrm{albedo} \mathrm{of} \mathrm{snow}}$?

A.  $\frac{1}{2}$

B.  $\frac{3}{4}$

C.  $\frac{4}{3}$

D.  2

Light of intensity 500 W m⁻² is incident on concrete and on snow. 300 W m⁻² is reflected from the
concrete and 400 W m⁻² is reflected from the snow.

What is $\frac{\mathrm{albedo} \mathrm{of} \mathrm{concrete}}{\mathrm{albedo} \mathrm{of} \mathrm{snow}}$?

A.  $\frac{1}{2}$

B.  $\frac{3}{4}$

C.  $\frac{4}{3}$

D.  2

Light of intensity 500 W m⁻² is incident on concrete and on snow. 300 W m⁻² is reflected from the
concrete and 400 W m⁻² is reflected from the snow.

What is $\frac{\mathrm{albedo} \mathrm{of} \mathrm{concrete}}{\mathrm{albedo} \mathrm{of} \mathrm{snow}}$?

A.  $\frac{1}{2}$

B.  $\frac{3}{4}$

C.  $\frac{4}{3}$

D.  2

Light of intensity 500 W m⁻² is incident on concrete and on snow. 300 W m⁻² is reflected from the
concrete and 400 W m⁻² is reflected from the snow.

What is $\frac{\mathrm{albedo} \mathrm{of} \mathrm{concrete}}{\mathrm{albedo} \mathrm{of} \mathrm{snow}}$?

A.  $\frac{1}{2}$

B.  $\frac{3}{4}$

C.  $\frac{4}{3}$

D.  2