Question

Consider the following:

A) The average irradiance of the Earth Surface is around 1000 watts per square meter

B) On a bright summer day, the daylight has a flux of around 10,000 lumens per square foot

C) Nuclear Fission is the main reason for the Sun's hot surface

The correct statements are

1. A, B and C
2. A and B
3. A and C
4. B and C
5.

Answer 1

Correct Answer - Option 2 : A and B

The correct answer is A and B.

• The Sun's rays are attenuated as they pass through the atmosphere, leaving maximum normal surface irradiance at approximately 1000 W/m2 at sea level on a clear day.
• The average annual solar radiation arriving at the top of the Earth's atmosphere is roughly 1361 W/m².
• On a bright summer day, the daylight has a flux of around 10,000 lumens/foot².
• The core of the sun is so hot and there is so much pressure, nuclear fusion takes place: hydrogen is changed to helium. 
• Hence, statement A and statement B are correct while statement C is incorrect.

• The lux is the SI-derived unit of illuminance, measuring luminous flux per unit area.
• It is equal to one lumen per square meter.