Physics

dW? = Eqdx
∫ dU? = ∫ kQ/x² dxq
W? = kQq (-1/x)|? ^ (R+y)
W? = kQq (y)/ (R) (R + y)
W? + W? = 1/2 mv²
V² = 2/m (kQqy/ (R) (R+y) + mgy)
V² = 2y (kQq/ (m (R) (R+y) + g) ; k = 1/ (4πε? )

1/4 m (210)² = m (0.03) x (4.2) x 1000 x ΔT ; Q = mSΔt
ΔT = (210) (210)/ (4) (4.2) (0.03) (1000) = 87.5°C

Photodiode operate in reverse bias. The photocurrent increases initially and saturates fi

f = V (n)/ (4 (1 - 17/100) (as closed from end)
f = (n - 2) (v)/ (4 (1 - 24.5/100)
nV (100)/4 (83) = (n - 2) (v) (100)/ (4) (75.5)
75.5n = 83 (n - 2)
75.5n = 83 (M - 2)
7.5n = 166
n = 22 (approx)
f = (330) (22) (100)/ (4 (83) = 2200 Hz

As Torque net = 0
Hence, L = constant
Iω = (3I + I)ω'
ω' = ω/4
Loss in K.E. = 1/2 Iω² - 1/2 (I + 3I)ω²/16 = 1/2 Iω² (1 - 1/4)
Fractional loss = (3/4 * 1/2 Iω²)/ (1/2 Iω²) = 3/4

As it just floats B = mg
(4πR³/3) (ρ‎? ) (g) = (4πR³/3 - 4πr³/3) (ρ‎? ) (g)
R³ = (R³ - r³) (27/8)
On solving we get,
r = 8/9 R (approx)

Refractive index (n) is a dimensionless quantity that has no units. Since both numerator and denominator are in meters per seconds (m/s), both units cancel each other. This makes refractive index simply a number. 

Absolute refractive index is the ratio of speed of light in air/vacuum to speed of light in any medium. It is closely related to refractive index, except that it is relative to vacuum and not to any other medium. This is different from relative refractive index because it is the ratio of speed of light in one medium compared to the speed of light in another medium.

This type of refraction is the bending of light rays when they pass through the atmosphere of Earth because of the change in the air density. The density of air varies with pressure and temperature. 

Due to the atmospheric refraction, celestial objects appear higher than they actually are. This leads to an advanced sunrise and a delayed sunset as well as the twinkling of stars.

When light from space enters the Earth's atmosphere, it slows down and changes direction as light moves from a rarer to a denser medium, which causes refraction.