B. At the equator
Explanation:
The energy coming from the Sun hits the Earth's surface at different angles, depending on the latitude of the place. The more perpendicular the ray of lights hit the surface, the more the energy transmitted to the Earth's surface, the warmer the location.
The angle at which the ray of lights hit the Earth is related to the latitude: in particular, the ray of lights arrive perpendicular at the equator (
), they arrive at larger angle in the United States (which is located at intermediate latitudes) and they arrive at the largest angles at the poles. For this reason, the sun's most energy is concentrated at the equator.
Complete Question
The complete question is shown on the first uploaded image
Answer:
a

b
New 
Explanation:
From the question we are told that
The refractive index of the core is 
The refractive index of the cladding is 
Generally according to Snell's law

Where
is the largest angle a largest angle a ray will make with respect to the interface of the fiber and experience total internal reflection
![\theta_{max} = 90 - sin^{-1} [\frac{n_{cladding}}{n_{core}} ]](https://tex.z-dn.net/?f=%5Ctheta_%7Bmax%7D%20%3D%2090%20-%20sin%5E%7B-1%7D%20%5B%5Cfrac%7Bn_%7Bcladding%7D%7D%7Bn_%7Bcore%7D%7D%20%5D)
![\theta_{max} = 90 - sin^{-1} [\frac{1.421}{1.497}} ]](https://tex.z-dn.net/?f=%5Ctheta_%7Bmax%7D%20%3D%2090%20-%20sin%5E%7B-1%7D%20%5B%5Cfrac%7B1.421%7D%7B1.497%7D%7D%20%5D)

Given from the question the the largest angle is 5°
Generally the refraction index of the cladding is mathematically represented as


Answer:
Explanation:
Stefan's Boltzman Law gives the value of radiation from a black body at a particular temperature. The relation is
E = eσ ( T₂⁴ -T₁⁴ )
e is emmisivity , σ is a constant = 5.67 x 10⁻⁸ , E is energy emitted per unit time per unit area
E = .915 x 5.67 x 10⁻⁸ x ( 303⁴ -293⁴ )
= .915 x 5.67 x 10⁻⁸ x ( 84.28 -73.70 ) x 10⁸
= 55 W / m²s
Area A = 1.45 m²
time t = 14.3 min
= 858 s
Total radiation
= 55 x 858 x 1.45 W
= 68425 J
Answer:
Solar eclipses result from the Moon blocking the Sun relative to the Earth; thus Earth, Moon and Sun all lie on a line. Lunar eclipses work the same way in a different order: Moon, Earth and Sun all on a line. In this case the Earth's shadow hides the Moon from view.