Concept explainers
(a)
The light intensity at the surface of the light bulb.
(a)
Answer to Problem 36.83AP
The light intensity at the surface of the light bulb is
Explanation of Solution
Given info:
The diameter of the spherical light bulb is
Formula to calculate the intensity at the surface of the light bulb is,
Here,
Substitute
Conclusion:
Therefore, the light intensity at the surface of the light bulb is
(b)
The light intensity at a distance
(b)
Answer to Problem 36.83AP
The light intensity at a distance
Explanation of Solution
Given info: The diameter of the spherical light bulb is
Formula to calculate the intensity at a distance
,
Here,
Substitute
Conclusion:
Therefore, the light intensity at a distance
(c)
The diameter of the light bulb image.
(c)
Answer to Problem 36.83AP
The diameter of the light bulb image is
Explanation of Solution
Given info: The diameter of the spherical light bulb is
From the lens maker formula,
Here,
Substitute
Thus, the image distance is
Formula to calculate the magnification of the image,
Here,
Formula to calculate the magnification of the image in terms of image and object distance is,
Here,
Equate the equation (1) and (2) and then rearrange for
Substitute
Conclusion:
Therefore, the diameter of the light bulb image is
(d)
The light intensity of the image.
(d)
Answer to Problem 36.83AP
The light intensity of the image is
Explanation of Solution
Given info: The diameter of the spherical light bulb is
From part (b) the light intensity at a distance
From part (c) the diameter of the light bulb image is
Formula to calculate the power of lens is,
Here,
The area of the lens is,
Substitute
The area of the lens is
Substitute
Formula to calculate the required intensity of bulb light image,
The area of image is,
Substitute
Substitute
Conclusion:
Therefore, the light intensity of the image is
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Chapter 36 Solutions
Physics for Scientists and Engineers
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