A convex lens of focal length 20 cm produces images of the same magnification 2 when an object is kept at two distances x1 and x2(x1 x2) from the lens. The ratio of x1 and x2 is :-

Question

A convex lens of focal length 20 cm produces images of the same magnification 2 when an object is kept at two distances x1 and x2(x1 > x2) from the lens. The ratio of x1 and x2 is :- (A) 5: 3 (B) 2: 1 (C) 4: 3 (D) 3: 1

Tardigrade Admin · Accepted Answer

Magnification is 2 If image is real, x1=(3 f/2) If image is virtual, x2=(f/2) ( X 1/ X 2)=3: 1

Q. A convex lens of focal length $20 c m$ produces images of the same magnification $2$ when an object is kept at two distances $x_{1}$ and $x_{2} (x_{1} > x_{2})$ from the lens. The ratio of $x_{1}$ and $x_{2}$ is :-

$5 : 3$

$2 : 1$

$4 : 3$

$3 : 1$

Magnification is $2$
If image is real, $x_{1} = \frac{3 f}{2}$
If image is virtual, $x_{2} = \frac{f}{2}$
$\frac{X _{1}}{X _{2}} = 3 : 1$

Q. A convex lens of focal length 20cm produces images of the same magnification 2 when an object is kept at two distances x1​ and x2​(x1​>x2​) from the lens. The ratio of x1​ and x2​ is :-

5:3

2:1

4:3

3:1