8 original questions from New Regents. The worksheet, answer key, and browser practice are free.
Photon Energy Comparisons 4 questions
Photon Energy Comparisons
New Regents original practice • Name: ____________________ Date: __________ Show your work for written answers.
Use E = hf, where h = 6.626 × 10-34 J·s. For electromagnetic waves in vacuum, use c = fλ with c = 3.00 × 108 m/s.
Question 1
If frequency triples, how does the energy of one photon change?
- It becomes one-third as large.
- It stays the same.
- It triples.
- It becomes nine times as large.
Question 2
Calculate the energy of one photon with frequency 5.00 × 10¹⁴ Hz. Round to three significant figures.
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Question 3
Which photon has the greater energy, a 500 nm photon or a 1,000 nm photon?
- The 500 nm photon
- The 1,000 nm photon
- Both have equal energy.
- Wavelength gives no information about energy.
Question 4
Two beams have the same photon frequency. One delivers twice as many photons per second to a detector. Compare their energy per photon and total energy delivered per second.
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Sources for a Photon Detector 4 questions
Sources for a Photon Detector
Use the information below to answer the questions.
A model detector responds to single photons only when their energy is at least 4.00 × 10-19 J. Three sources supply photons of the listed frequencies.
| Source | Frequency (Hz) |
|---|---|
| P | 4.00 × 1014 |
| Q | 5.50 × 1014 |
| R | 7.00 × 1014 |
Question 5
Which source provides photons that meet the detector’s energy requirement?
- P only
- Q only
- R only
- P and Q
Question 6
Calculate the minimum frequency that reaches the detector’s energy requirement.
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Question 7
Which source’s photons have the longest wavelength in vacuum?
- P
- Q
- R
- All three have the same wavelength.
Question 8
Suppose source Q emits more photons per second at the same frequency. Explain whether each photon now meets the threshold.
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