Radiation Laws

Question 0

Describe the relationship between black bodies and radiation.

Answer 0

Theoretical bodies capable of absorbing all radiation incident upon them and re-emitting maxum possible

Question 1

Define emissivity.

Answer 1

For all bodies the ratio of intensity of emission to fractional absorption is a function of wave length and temperature only.

Question 2

Name the radiation laws that determine wavelnghth characteristics

Answer 2

Planck’s Law.
Wien’s Law.
Stefan-Boltzmann Law

Question 3

Define Planck’s Law

Answer 3

Radiation emitted by a body as a function of wavelength and temperature
Elambda = C1/lambda^5

Question 4

Define Wien’s Law

Answer 4

Wavelength at which max emission, lambda m, of radiation occurs
Wavelength

Question 5

Define Wien’s Displacement Law

Answer 5

Lambda m = 2897/T

Sun = 2897/T = 2897/6000 = 0.5 microns

Earth = 2897/288 = 10 microns

Question 6

Define Stefan-Boltzmann Law

Answer 6

Te energy emitted by a body is directly proportional to the fourth power of tye temp of thy body

Hot bodies emit a lot more radiation than cooler bodies

Emission =

Question 7

Describe the problems of auditing disaster

Answer 7

There is no agreed definition of disaster, therefore the reporting and archiving (=auditing) of disasters is inconsistent
Reporting is biased to the dramatic, rapid-onset event
Reporting is biased towards western prespective

Question 8

The method

Answer 8

Tr(yers) = (n+1)/m
P(%) = 100/Tr
1/Tr(years) = AF

m - event ranking
n - number if events im the period record
Tr - recurrence interval
AF - annual frequency