Question

A candle is placed in front of a convex lens with a focal length of 5 cm. The image of the candle is focused on a sheet of paper that is exactly 15 cm behind the lens. What is the distance from the candle to the lens? _______________ Show your work:

Answer 1

Answer:

by using lens formula we can find the distance of the candle placed in front of convex lens

HOPE IT IS USEFUL!

Answer 2

7.5 cm

A Convex Lens is a curved transparent medium made of glass that seems to be a component of a compact spherical. The Convex Lens's surface has an exterior curvature that resembles the surface of a glass ball. When light rays strike the Lens's Convex surface, they tend to converge from their courses, and biConvex Lenses are formed when both surfaces are Convex, while plano-Convex Lenses are formed when one surface is flat and the other is Convex.

According to Lens formula,

$\frac{1}{v}$ - $\frac{1}{u}$ = $\frac{1}{f}$

where, v = distance of image

u = distance of object

f= focal length of lens.

∴ $\frac{1}{u}$ = $\frac{1}{15}$ - $\frac{1}{5}$

∴ u = - 7.5 cm

Here, the negative sign indicates that the object is on the opposite side of the lens.