Physics

Question 1

Wave Number (k)

Answer 1

k = 2pi/lambda

Question 2

Impedance of waves on a string (z)

Answer 2

z = linear mass density( * velocity

Question 3

Tension on a String

Answer 3

v = sqrt (T/rho)

Question 4

Compton Effect

Answer 4

delta lambda = scattered - initial = h/mc(1-cosθ)

Question 5

de Broglie Wavelength

Answer 5

λ = h/p

Question 6

Momentum

Answer 6

p = E/c

Question 7

de Broglie wavelength of an electron

Answer 7

λ = h/sqrt(2meV)

Question 8

Uncertainty Principle

Answer 8

Δx.Δp >= ħ/2

Question 9

Transmission Probability

Answer 9

T = e^-2ka
where
k = sqrt(2m(Vo - E))/ħ

Question 10

Probability of finding a particle in a 1D box

Answer 10

2/L*[integration of sin^2(npix/L) from a to b]

Question 11

Threshold Grain Coefficient

Answer 11

Kth = γ + 1/2L*ln(1/R1R2)
where
γ = loss coefficient
R1,R2 are mirror reflectivity

Question 12

Temporal Coherence Length

Answer 12

L = λ^2/Δλ
where
λ = central wavelength
Δλ = spectral width

Question 13

Ratio of population

Answer 13

A21/B21 = 8pihv^3/c^3 and B21 = B12

Question 14

Criticial Angle

Answer 14

θc = sin^-1(n2/n1)

Question 15

Propagation Angle

Answer 15

α = cos^-1(n2/n1)

Question 16

Numerical Aperture

Answer 16

sinθa = sqrt(n1^2-n2^2)

Question 17

V Parameter

Answer 17

V = (2pia/λ)*NA

Question 18

Attenuation (Loss of Signal Power)

Answer 18

α = (10/L)*log10(Pin/Pout)

Question 19

Responsivity

Answer 19

R = (η*q)/hν

Question 20

Quantum Efficiency

Answer 20

η = (number of charge carriers)/(number of incident photons)

Question 21

Energy of particle in 1D

Answer 21

E = (n^2pi^2ħ^2)/2ma^2

Question 22

Relative refractive index

Answer 22

Δ = (n1-n2)/n1

Question 23

Fundamental Frequency

Answer 23

f = v/2L

Question 24

Bandgap Energy for a semiconductor

Answer 24

E = 1240/λ