A convex mirror of focal length f forms an image which is (1/n) times the object. The distance of the object from the mirror is

Question

A convex mirror of focal length f forms an image which is (1/n) times the object. The distance of the object from the mirror is (A) -(n-1) f (B) -((n-1/n)) f (C) ((n+1/n)) f (D) (n+1) f

Tardigrade Admin · Accepted Answer

m=+(1/n)=-(v/u) ⇒ v=-(u/n) By using mirror formula (1/f)=(1/-(u)n)+(1/u) ⇒ u=-(n-1) f

Q. A convex mirror of focal length $f$ forms an image which is $\frac{1}{n}$ times the object. The distance of the object from the mirror is

$- (n - 1) f$

$- (\frac{n - 1}{n}) f$

$(\frac{n + 1}{n}) f$

$(n + 1) f$

$m = + \frac{1}{n} = - \frac{v}{u} \Rightarrow v = - \frac{u}{n}$
By using mirror formula $\frac{1}{f} = \frac{1}{- \frac{u}{n}} + \frac{1}{u}$
$\Rightarrow u = - (n - 1) f$

Q. A convex mirror of focal length f forms an image which is n1​ times the object. The distance of the object from the mirror is

−(n−1)f

−(nn−1​)f

(nn+1​)f

(n+1)f