Bright Star

1. 1
 
 
20,000 . min
,
max ?
( )
A certain very bright star has an
effective surface temperature of
K a Assu g that it
radiates as a blackbody what is
the wavelength at which u is
imum b In what part of
the electromagne

max ?
tic spectrum
does the imum lie
Solution

2. 2
3
3 3
3 4 7
8 9
( ) According to Wien displacement
law for a blackbody:
2.90 10 .
2.90 10 . 2.90 10 .
20000
1.45 10 10 1.45 10
14.5 10 145 10 145
m
m
a
T m K
m K m K
T K
X X m X m
X m X m nm



 
  
 
 
 
  
 
  

3. 3
 
  " "
.
.
int
: 4
b
Ultraviolet UV light is a type of
electromagnetic radiation UV light
has a shorter wavelength than visible
light In physics ultraviolet radiation
is traditionally divided o four
regions near  
 
 
 
00 – 300 ,
300 – 200 ,
200 –100 ,
100 .
,
.
m
nm
middle nm
far nm and
extreme below nm
Hence
falls under ultraviolet region
within the electromagnetic spectrum
