The real image of an object formed by a converging lens of focal length 15cm, is three times the size of the object. Calculate the object distance
Question 1 Report
The real image of an object formed by a converging lens of focal length 15cm, is three times the size of the object. Calculate the object distance
Answer Details
The magnification produced by a lens is given by the ratio of the size of the image to the size of the object:
magnification = size of image / size of object
In this case, we are given that the size of the image is three times the size of the object, so the magnification is:
magnification = 3/1 = 3
We can also use the formula for the magnification produced by a converging lens:
magnification = -image distance / object distance
where the negative sign indicates that the image is inverted. We know the focal length of the lens is 15 cm. We can substitute in the known values and solve for the object distance:
3 = -image distance / object distance
image distance = -3 object distance
1/f = 1/image distance + 1/object distance
1/0.15 = 1/-3x + 1/x
x = 20 cm
Therefore, the object distance is 20 cm.
Answer: 20cm
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