The focal length of a concave mirror is $50 cm$ . Where should the object be placed so that the size of the image is two times the size of the object and inverted?

Question

The focal length of a concave mirror is 50 cm where an object is to be placed so that its image is two times magnified- real and inverted -72 cm63 cm75 cm50 cm

Toppr Admin · Accepted Answer

Given-Focal length- f-50cmMagnification- m-2 m-vu-2v-2u From mirror-formula-1f-1v-1u 1f-12u-1u-u-3f2-3-xD7-502-75-xA0-cm -Object Is-placed at 75cm from the mirror-

The focal length of a concave mirror is $50 c m$ where an object is to be placed so that its image is two times magnified, real and inverted :
$72 c m$
$63 c m$
$75 c m$
$50 c m$

Given,
Focal length, $f = 50 c m$
Magnification, $m = 2$
$m = \frac{v}{u} = 2$
$v = 2 u$
From mirror formula,
$\frac{1}{f} = \frac{1}{v} + \frac{1}{u}$
$\frac{1}{f} = \frac{1}{2 u} + \frac{1}{u}$
$u = \frac{3 f}{2} = \frac{3 \times 50}{2} = 75 c m$

Object Is placed at $75 c m$ from the mirror.

The focal length of a concave mirror is 50cm where an object is to be placed so that its image is two times magnified, real and inverted :72cm63cm75cm50cm

Given,Focal length, f=50cmMagnification, m=2 m=vu=2v=2u From mirror formula,1f=1v+1u 1f=12u+1u u=3f2=3×502=75 cm Object Is placed at 75cm from the mirror.

The focal length of a concave mirror is $50 c m$ where an object is to be placed so that its image is two times magnified, real and inverted :
$72 c m$
$63 c m$
$75 c m$
$50 c m$

Given,
Focal length, $f = 50 c m$
Magnification, $m = 2$
$m = \frac{v}{u} = 2$
$v = 2 u$
From mirror formula,
$\frac{1}{f} = \frac{1}{v} + \frac{1}{u}$
$\frac{1}{f} = \frac{1}{2 u} + \frac{1}{u}$
$u = \frac{3 f}{2} = \frac{3 \times 50}{2} = 75 c m$

Object Is placed at $75 c m$ from the mirror.