The intensity of solar radiation of the earths surface is `1KWm^(-2)`. The power entering the pupil of an eye of diameter `0.5 cm` is

Average intensity of the solar energy incident on the earth's surface is 1300 W.m^(-2) . Calculate the rms values of electric and magnetic fields due to this radiation near the earth's surface. (Given mu_0=4pixx10^(-7)H.m^(-1) )

The intensity of solar radiation just outside the earth's atmosphere is measured to be 1.4 kW//m^2 . If the radius of the sun 7xx10^8m , while the earth-sun distance is 150xx10^6km , then find i. the intensity of salr radiation at the surface of the sun. ii. the temperature at the surface of the sun assuming it to be a black body, iii. the most probable wavelength in solar radiation.

The intensity of salr radiation just outside the earth's atmosphere is measured to be 1.4 kW//m^2 . If the radius of the sun 7xx10^8m , while the earth-sun distance is 150xx10^6km , then find i. the intensity of salr radiation at the surface of the sun. ii. the temperature at the surface of the sun assuming it to be a black body, iii. the most probable wavelength in solar radiation.

A normal human eye can detect yellow light if more than 10 photons enter into it per second. A star is generating as much power as the Sun and is emitting predominantly yellow light (lambda = 6000 Å) . How far is the star if our eye isbarely able to see it? It is given that intensity of solar light on surface of the earth is I = 1400 Wm^(– 2) and the distance of the Sun from the Earth is r = 1.5 × 10^(11) m . The diameter of pupil of our eye is d = 6 mm .

What percentage of solar radiation that hits the Earth's atmosphere ever reaches the surface?

Solar constant, I_(s) is defined as intensity of solar radiation incident on the Earth. Its value is close to 1.4 kW//m^(2) . Nearly 68% of this energy is absorbed by the Earth. The average temperature of Earth is about 290 K. Radius of the Earth is R_(e) = 6000 km and that of the Sun is R_(s) = 700,000 km . Earth - Sun distance is r = 1.5 xx 10_(8) km . Assume Sun to be a black body. (a) Estimate the effective emissivity of earth. (b) Find the power of the sun. (c) Estimate the surface temperature of the Sun.

Find the number of photons entering the pupil of our eye per second corresponding to the minimum internsity of white light that we humans can perceive (-10^(-10) Wm^(-2)) . Take the area of the pupil to be about 0.4 cm^(2) , and the average frequency of white light to be about 6xx10^(14) Hz .