Which of the following is the value of the solar constant?

Question

Which of the following is the value of the solar constant?

1. A. 1.6 kW/m²
2. B. 1.4 kW/m² (Correct answer)
3. C. 1.2 kW/m²
4. D. 1.8 kW/m²

Correct Answer

Option B — 1.4 kW/m²

Detailed Solution & Explanation

The correct answer is 1.4 kW/m².

Key Points

• The solar constant is approximately 1.4 kW/m² (about 1.36-1.37 kW/m², or roughly 1360-1370 watts per square metre). It is defined as the amount of solar energy received per unit area per unit time on a surface held perpendicular to the Sun's rays at the top of the Earth's atmosphere, at the mean Earth-Sun distance.
• Among the given options, the value closest to the accepted solar constant is 1.4 kW/m², making option (B) correct.

Additional Information

• this value represents the incoming solar radiation before it is reduced by absorption and scattering in the atmosphere.
• It is fundamental to studies of climate, weather and solar energy.