00:01
Hi everyone, we have a question in which the question says an object which is 5 cm tall is placed perpendicular to the principal axis of a convex lens having a focal length of 20 centimeter.
00:13
So in the question this is given, there is a convex lens having a focal length of 20 centimeter.
00:20
So for a convex length, the focal length is f which will be positive since it is a convex lens.
00:28
So it will become up 20 cm because it is on the right side of the lens.
00:33
And also this is given the height of the object.
00:36
So height of the object is also given.
00:38
Height of object, let's say h1 is also given in the question.
00:44
So h1 is equals to 5 centimeter.
00:48
Now we will take it as an erect object.
00:50
So it will be plus of 5 centimeter.
00:54
Now this is also given in the question.
00:58
The object is placed from the lens.
01:00
At a 30 centimeter that means object distance is also given object distance is also given so object distance let's say you is given in the question which is equals to 30 centimeters so we will take on the left side of the lens so it will be minus of 30 because the object is placed on the left side of the lens so from here we need to find the magnification or we or we can say we need to find the size of the image but therefore we need to find the size of image so for finding the size of image first we need to find the magnification so let's see how can we do this question now from the magnification of a lens from magnification from magnification we know that for a lens m is equals to height of image divided by height of object or we can see the size of image divided by size of object which is equals to distance of image from the length lens divided by distance of object from the lens.
02:04
So we will apply this part here and we can find the size of the image.
02:09
So size of the image which is taken as h2 is equals to h1 multiplied by v by u.
02:17
So placing the values here...