IB Physics Greenhouse effect Practice Questions

Q: The solar constant, the mean intensity of solar radiation at the top of Earth's atmosphere, is approximately:

$1.36\times 10^{3}\,\text{W m}^{-2}$. The solar constant is about $1.36\times 10^{3}\,\text{W m}^{-2}$.

Q: The main greenhouse gas released by the combustion of fossil fuels is carbon _____.

dioxide. Burning hydrocarbons produces carbon dioxide ($\text{CO}_{2}$), the dominant anthropogenic greenhouse gas.

Question 1

Which of the following is a greenhouse gas?

Accepted Answer

Carbon dioxide. Carbon dioxide strongly absorbs and re-emits infrared radiation, making it a greenhouse gas. Methane and water vapour are others.

Question 2

The albedo of a surface is defined as:

Accepted Answer

The fraction of incident radiation reflected. Albedo is the fraction of incident radiation that is reflected. Light surfaces (ice) have high albedo; dark surfaces (ocean) low.

Question 3

Solar radiation of power $P$ falls normally on an area $A$. The intensity is given by:

Accepted Answer

$I=\frac{P}{A}$. Intensity is power per unit area, $I=\frac{P}{A}$, measured in $	ext{W m}^{-2}$.

Question 4

The solar constant, the mean intensity of solar radiation at the top of Earth's atmosphere, is approximately:

Accepted Answer

$1.36	imes 10^{3}\,	ext{W m}^{-2}$. The solar constant is about $1.36	imes 10^{3}\,	ext{W m}^{-2}$.

Question 5

Greenhouse gases warm the Earth mainly because they:

Accepted Answer

Absorb outgoing infrared radiation and re-emit some back to the surface. The Earth emits longer-wavelength infrared radiation. Greenhouse gases absorb this outgoing infrared and re-radiate some back toward the surface, warming it.

Question 6

For the Earth to remain at a stable average temperature, the power it radiates must:

Accepted Answer

Equal the power it absorbs from the Sun. Energy balance requires the radiated power to equal the absorbed solar power; otherwise the planet warms or cools.

Question 7

The fraction of incident solar radiation that a surface reflects is called its _____.

Accepted Answer

albedo. Albedo ranges from 0 (perfect absorber) to 1 (perfect reflector).

Question 8

The main greenhouse gas released by the combustion of fossil fuels is carbon _____.

Accepted Answer

dioxide. Burning hydrocarbons produces carbon dioxide ($	ext{CO}_{2}$), the dominant anthropogenic greenhouse gas.

Question 9

Which statements about Earth albedo are correct? I It varies daily.  II It depends on latitude.  III It depends on cloud cover.

Accepted Answer

I, II and III. Albedo changes with daily conditions, latitude (ice and angle) and cloud cover, so all three are correct.

Question 10

The albedo of a surface is defined as the ratio of

Accepted Answer

reflected power to incident power. reflected (scattered) power to the total incident power.

IB Physics: Greenhouse effect — Practice Questions & Answers

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