CBSE Class 10CBSE
Share
Notifications

View all notifications

An Object of 5.0 Cm Size is Placed at a Distance of 20.0 Cm from a Converging Mirror of Focal Length 15.0 Cm. at What Distance from the Mirror Should a Screen Be Placed to Get the Sharp Image? Also Calculate the Size of the Image. - CBSE Class 10 - Science

Login
Create free account


      Forgot password?

Question

An object of 5.0 cm size is placed at a distance of 20.0 cm from a converging mirror of focal length 15.0 cm. At what distance from the mirror should a screen be placed to get the sharp image? Also calculate the size of the image.

Solution

Concave mirror is a converging mirror.
Distance of the object from the mirror 'u' = -20 cm
Height of the object 'ho' = 5 cm
Focal length of the mirror 'f' = -15 cm
We have to find the distance of the image 'v' and the height of the image 'hi'.
Using the mirror formula, we get 
`1/f=1/v+1/u` 
`1/-15=1/v+1/-20=1/v-1/20` 
or` 1/v=1/20-1/15` 
`or 1/v=(3-4)/60=1/60` 
`or v=-60` cm 
Thus, the image is at a distance of 60 cm in front of the mirror.  
Now, using the magnification formula, we 
 get 
`m=-v/u=h_i/h_o`  
or `h_i/5=-(-60)/-20`  
or h_i/5=-3 
or `h_i =-3xx5=-15` cm 
Therefore, the height of the image will be 15 cm, and the negative sign shows that the image will be formed below the principal axis
  Is there an error in this question or solution?

APPEARS IN

Solution An Object of 5.0 Cm Size is Placed at a Distance of 20.0 Cm from a Converging Mirror of Focal Length 15.0 Cm. at What Distance from the Mirror Should a Screen Be Placed to Get the Sharp Image? Also Calculate the Size of the Image. Concept: Reflection of Light - Image Formation by Spherical Mirrors - Concave Mirror.
S
View in app×