Concept explainers
(a)
The number of photons that enter the telescope.
(a)
Answer to Problem 63P
The number of photons detected by the detector is
Explanation of Solution
Write the expression for the power of the incident photons per second on the detector.
Here,
Write the expression for the energy per second detected by the detector of telescope.
Substitute
Here,
Write the expression for the energy of the incident photon of particular wavelength.
Here,
Write the expression for the number of photons incident on the detector.
Here,
Conclusion:
Substitute
Substitute
Substitute
Thus, the number of photons detected by the detector is
(b)
The number of photons reaching the retina at the
(b)
Answer to Problem 63P
The number of photons detected by the detector is
Explanation of Solution
Write the expression for the intensity of the
Here,
Conclusion:
Substitute
Substitute
Substitute
Thus, the number of photons detected by the detector is
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Chapter 3 Solutions
Modern Physics for Scientists and Engineers
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