Question

Ram, a science student, is trying to find the nature of a mirror he found in the lab. For doing that, he set up an experiment. He kept a candle in front of the mirror and a screen behind the candle. Now he started moving the screen until he got a clear image on the screen. Once the image is obtained, he measures and makes a note of the distances between the mirror, candle, and screen as shown.


Ram noticed that the image of the flame of the candle formed on the screen looks bigger. How much bigger in size is the image of the flame?

[0.8 mark]

• A. Twice the size of the original
• B. Three times the size of the original
• C. Four times the size of the original
• D. Five times the size of the original

Answer 1

The correct option is B Three times the size of the original

Magnification is given by:

$m=\frac{Heightofimage\left(I\right)}{Heightofobject\left(O\right)}=-\frac{v}{u}$

$m=-\frac{(-120)}{(-40)}=-3$

The size of the image of the flame is three times the size of the original.