Question

# An object is kept in front of a concave mirror of focal length 20 cm. The image is three times the size of the object.Calculate two possible distance of the object from the mirror.

Solution
Verified by Toppr

#### It is given that,Focal lengthf=−20cmhi=3hoThe image is three times the size of the object. So there are two cases.Case 1. For real imagem=−vu=−3v=3uUsing mirror’s formula1f=1v+1u1−20=13u+1uu=−803cmCase 2. For virtual imagem=−vu=+3v=−3uAgain using mirror’s formula1−20=1−3u+1uu=−403cmThe possible values of u are −803cmand−403cm.

9
Similar Questions
Q1

An object is kept behind a concave mirror of focal length 20cm.the image is three times the object size. Calculate two possible distances of the object from the mirror.

View Solution
Q2

The focal length of a concave mirror is 30 cm. Find the distance of the object in front of the mirror, so that the image is three times the size of the object.

View Solution
Q3

A concave mirror has a focal length of 20 cm. The distance between two possible positions of the object for which the image size is double of the object size is

View Solution
Q4

An object is placed at a distance of 20 cm in front of a concave mirror of focal length 10 cm. Calculate the magnification of the image produced by the mirror.

View Solution
Q5

An object is placed at a distance of 20 cm in front of a concave mirror of focal length 10 cm. Calculate the image distance (in cm).

View Solution
Solve
Guides