The image formed by spherical mirror is real, inverted and its magnification 2. if the image is at a distance of 30 cm from the middle ,where is the object placed ?find the focal length of the mirror. list two characteristics of the image formed if the object is moved attention towards the mirror.
Answers
Hey buddy,
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◆ Answer-
u = -15 cm
f = -10 cm
◆ Explanation-
# Given-
M = -2
v = -30 cm
# Solution-
Magnification by mirror is calculated by-
M = -v / u
-2 = -(-30) / u
u = -15 cm
Focal length is calculated by-
1/f = 1/u + 1/v
1/f = -1/15 - 1/30
1/f = -3/30
f = -10 cm
When object is moved 10 cm towards mirror,
u' = -15+10 = -5 cm
Using mirror formula-
1/f = 1/v' + 1/u'
-1/10 = 1/v' - 1/5
v' = 10 cm
From this, we can say that-
- Image formed is erect and virtual in nature.
- Image formed is magnified.
Hope this helps you...
Answer:
Given :
Magnification m = - 2
Image distance v = 30 cm
We know :
m = - v / u
- 2 = - (- 30 ) / u
u = - 15 cm
We have mirror formula :
1 / f = 1 / v + 1 / u
1 / f = 1 / - 15 - 1 / 30
1 / f = - 1 / 10
f = - 10 cm
When the object is moved 10 cm towards the mirror.
Then : u' = u - 10 cm
= > u' = - 5 cm
Again putting in formula to get v'
1 / - 10 + 1 / 5 = 1 / v'
1 / v' = 2 - 1 / 10
v' = 10 cm
Therefore , the image is located 10 cm behind the mirror.
Also new magnification :
m' = -v' / u'
m' = - 10 / -5
m' = 2
Since magnification is positive the image is erect and virtual.
Also image is magnified in nature.