size of image of an object formed by a mirror having a focal length of 20cm is observed to be reduced to 1/3rd of its size .at what distance of the object has been placed from the mirror? what is the nature of the image and the mirror?
Answers
Answered by
2
HII!
lets see the answer in cases!1
CASE 1:- m=-1/3(in case of concave mirror)
f= -20 cm
m= -1/3 =-v/u
v=u/3
1/f= 1/v +1/u .
=> -1/20 = 3/u + 1/ u= 4/u
therefore.,, u = -80 cm.
CASE 2:-
M=+1/3 (IN CASE OF CONVEX MIRROR)
f=+20 cm.
m=+1/3 =-v/u
v=-u/3.
i/f=1/v+1/u.
=> 1/20= -3/4 + 1/4 =-2/4
therefore, u= -40 cm....
HOPE IT WILL HELP YOU
lets see the answer in cases!1
CASE 1:- m=-1/3(in case of concave mirror)
f= -20 cm
m= -1/3 =-v/u
v=u/3
1/f= 1/v +1/u .
=> -1/20 = 3/u + 1/ u= 4/u
therefore.,, u = -80 cm.
CASE 2:-
M=+1/3 (IN CASE OF CONVEX MIRROR)
f=+20 cm.
m=+1/3 =-v/u
v=-u/3.
i/f=1/v+1/u.
=> 1/20= -3/4 + 1/4 =-2/4
therefore, u= -40 cm....
HOPE IT WILL HELP YOU
Similar questions