Question

A concave mirror produce six time magnified image of an object placed at 20 cm in front of it find the position of the image

Answer 1

Answer:

Given:

Magnification = 6 times

Object placed at 20 cm before the concave mirror.

To find:

Position of image.

Concept:

A concave mirror produces erect , magnified image only when , the object has been placed in between the focus and the mirror.

Calculation:

We know the relationship between object height , image height , object distance , image distance and magnification in case of lens.

$\boxed{ \bold{ \dfrac{H_{i}}{H_{o}} = - \dfrac{v}{u} = magnification}}$

Magnification is +6 , so we can say that :

$\bigstar \: \: - \dfrac{v}{u} = + 6$

$= > - \dfrac{v}{( - 20)} = + 6$

$= > v = + 120 \: cm$

Since the Image distance is positive, so the image will be virtual , erect and magnified.

Answer 2

Answer :

• Image is located at 120 cm

Explanation :

• Magnification (m) = 6
• Image distance (u) = - 20 cm
• Concave mirror

We know that,

$\longrightarrow \sf{m \: = \: \dfrac{-v}{u}} \\ \\ \longrightarrow \sf{6 \: = \: \dfrac{-v}{-20}} \\ \\ \longrightarrow \sf{6 \: = \: \dfrac{v}{20}} \\ \\ \longrightarrow \sf{v \: = \: 20 \: \times \: 60} \\ \\ \longrightarrow \sf{v \: = \: 120} \\ \\ \underline{\underline{\sf{Image \: Position \: is \: 120 \: cm \: from \: mirror}}}$

• Nature of Image is Virtual and Erect