Target Exam

CUET

Subject

Physics

Chapter

Ray Optics

Question:

If x and y be the distances of the object and image formed by a concave mirror from its focus and f be the focal length then

Options:

$xf = y^2$

$xy = f^2$

$x/y = f$

$x/y = f^2$

Correct Answer:

$xy = f^2$

Explanation:

According to Newton's formula $xy = f^2$.

Note that $m=\frac{f}{f-u}=\frac{f-v}{f}$

or $\frac{f}{x}=\frac{y}{x}⇒xy=f^2$