Question

A Plane Mirror Is Placed At A Distance Of 50Cm From A Concave Mirror Of Focal Length 16Cm. If A Short Object Be Placed Between The Mirrors And Facing Both The Mirrors To Each Other So That Its Virtual Image In The Plane Mirror Coincides With The Real Image In Concave Mirror. What Is The Ratio Of The Magnitude Of The Sizes Of The Image Formed By The Plane Mirror To The Size Of The Image Formed By The Concave Mirror?

Answer 1

Answer:

PHYSICS

A point object is kept between a plane mirror and a concave mirror facing each other. The distance between the mirrors is 22.5cm. Plane mirror is placed perpendicular to principal axis of concave mirror. The radius of curvature of the concave mirror is 20cm. What should be the distance of the object from the concave mirror so that after two successive reflections the final image is formed on the object itself? (Consider first reflection from concave mirror)

A .

5cm

B .

15cm

C .

10cm

D .

7.5cm

December 26, 2019Kanhaiya Rajora

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ANSWER

Concave mirror(flat reflection),

      v1+u1=f1−(45−x)1+−x1=−10145−x1+x1=101(45−x)xx+45−x=101450=45x−x2orx2−45x+450=0orx2−15x−30x+450=0or(x−15)−30(x−15)=