Question

An object is placed at a distance of 30cm from the pole of a curved concave or convex mirror of focal length 15cm. Then the linear magnification is

Answer 1

Hey!!
Let he object is placed at a distance of 30 cm from the mirror
Means u = -30cm

f = -15cm
Thus using mirror equation
1/f = 1/u +1/v
=> 1/v = 1/f-1/u
=> 1/v = -1/15+1/30
=> 1/v = -1/30
=> V = -30

Now lateral magnification
m = -(v/u) => -(30/30) = -1
Here -sign signifies that image is inverted .
From here we can also conclude that the object was placed at center.

now In case of convex mirror

u = -30
f = +15
Thus again applying mirror equation
1/f = 1/v +1/u
=>1/v = 1/15+1/30
=> 1/v = 3/30
=> v = 10
Magnification
m = -(v/u) = 10/30 => 1/3
It means that image formed will be virtual and shrinked