Distance between an object and its three times magnified real image is $40 \ cm$. The focal length of the mirror used is . . . . . . $cm$.

  • A
    $-7.5$
  • B
    $-10$
  • C
    $-20$
  • D
    $-15$

Explore More

Similar Questions

Use the mirror equation to deduce that:
$(a)$ an object placed between $f$ and $2f$ of a concave mirror produces a real image beyond $2f$.
$(b)$ a convex mirror always produces a virtual image independent of the location of the object.
$(c)$ the virtual image produced by a convex mirror is always diminished in size and is located between the focus and the pole.
$(d)$ an object placed between the pole and focus of a concave mirror produces a virtual and enlarged image.

In the figure shown,the image of a real object $O$ is formed at point $I$. $AB$ is the principal axis of the mirror. The mirror must be:

If $x$ is the distance of an object from the focus of a concave mirror and $y$ is the distance of the image from the focus, then which of the following graphs is correct between $x$ and $y$?

An object is placed $40\;cm$ from a concave mirror of focal length $20\;cm.$ The image formed is

$A$ spherical mirror forms an erect image of an object,three times the size of the object. If the distance between the object and the image is $80 \ cm$,then the focal length of the mirror is ......... $cm$.

Difficult
View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo