In the geometrical optics experiment, a student used a convex lens with 6 cm focal length to produce a large image of an object. The object was placed at a distance of 14 cm from the lens. What is the magnification of the image? include the sign.
Solution
In a convex lens all the light rays that enter parallel to its axis cross each other at a common point (focus) on the other side. If a point light source is placed on the focal point, the rays emerging from the lens will be parallel to each other. The rays passing through the centre of the lens does not change its path and is not diverted (negligible refraction).
The problem can be solved by using the thin lens equations,
1/do + 1/di =1/f , where,
do - distance of object from centre of lens = 14 cm.
di - distance of image from centre of lens.
f - focal length - distance of focus from centre of lens = 6 cm.
Substituting,
1/14 + 1/di = 1/6
gives, di = 10.5 cm
The magnification 'm' is given by :
m = di / do
Therefore, m = - 10.5/14 = -0.75 ..........(Ans.)
The minus sign indicates that the image is inverted.
The problem can also be solved by ray tracing method which is limited to the accuracy with which you draw.The thin lens equation produces more precise results limited only by the accuracy of the information given.
Figure below can help to solve using ray tracing method.Rays form the head of the person only is shown in figure. Similarly rays from all parts of the body helps in the image formation.
In the geometrical optics experiment, a student used a convex lens with 6 cm focal length...
A) In the geometrical optics experiment, a student used a convex lens with 7 cm focal length to produce a large image of an object. The object was placed at a distance of 13 cm from the lens. Find the location of the formed image with respect to the lens (in cm). B) In the geometrical optics experiment, a student performed an experiment to measure the focal length of a convex lens. The object was placed at a distance of...
An object is placed 6 cm from a convex lens of focal length 18 cm. what is the lateral magnification of the object.
The focal length of a convex lens is given to be 17 cm. It's magnification is -2.5. (a) What is the distance of the object and image from the lens? (b) What is the image height if the object is 15 cm? (c) Draw a ray diagram for this situation, label completely.
Please help with this practice question about optics! 6. A certain convex lens is used to create an image of an object that is 2.0 m in front of the lens on a white screen that is 15.0 cm behind the lens. For the sake of clarity in the description that follows, assume that the object, lens, and screen are on the x axis, the lens sits at the origin, and the object is in the positive x direction (so...
2. An object is placed 26.0 cm in front of convex lens of focal length 45.0 cm. What is the magnification of the image?
A convex lens has a focal length of 14.5 cm. Where on the lens axis should an object be placed in order to get a virtual, enlarged image with a magnification of 1.70? Answer in cm.
1. A 4.00-cm tall object is placed a distance of 48 cm from a concave mirror having a focal length of 16cm. Determine the image distance and the image size. 2. A 4.00-cm tall object is placed a distance of 8 cm from a concave mirror having a focal length of 16cm. Determine the image distance and the image size. 3. Determine the image distance and image height for a 5.00-cm tall object. placed 30.0 cm Infront of from a convex mirror...
An item is 20 em from a lens with a focal length of +12 em (convex lens). How far away must the screen be to produce a focused image, and what is the magnification of the image? Draw a rough picture of where the image is in relation to the object and the lens. 1. An item is 8 cm from a lens with a focal length of +12 cm (convex lens). Where does a focused image form? Can it...
A concave lens has a focal length of -36 cm. Find the image distance and magnification that results when an object is placed 19 cm in front of the lens. (Use the proper sign convention for both quantities.) When an object is located 61 cm to the left of a lens, the image is formed 25 cm to the right of the lens. What is the focal length of the lens? An object with a height of 2.22 cm is...
15. (3 points) A convex lens of focal length of 20 cm is used to form an image of an object on a screen. (The setup is somewhat similar to what you used in the lab however it is not exactly the same.) The height of the object is 20 mm and the height of the image on the screen is 40 cm. (Note UNITS in the previous sentence!) How far from the lens must the screen be placed? Report...