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The energy of a photon of frequency v is...

The energy of a photon of frequency v is E = hv and the momentum of a photon of wavelength `lambda` is p = `h/lambda` From this statement one may conclude that the wave velocity of light is equal to :

A

`3 xx 10^(8) ms^(-1)`

B

`(E)/(P)`

C

Ep

D

`((E)/(P))^(2)`

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The correct Answer is:
To find the wave velocity of light based on the given relationships for the energy and momentum of a photon, we can follow these steps: ### Step-by-Step Solution: 1. **Understand the Given Relationships**: - The energy \( E \) of a photon is given by the equation: \[ E = h \nu \] - The momentum \( p \) of a photon is given by the equation: \[ p = \frac{h}{\lambda} \] 2. **Recall the Wave Velocity Formula**: - The wave velocity \( v \) of any wave can be expressed as: \[ v = \lambda \nu \] - Here, \( \lambda \) is the wavelength and \( \nu \) is the frequency of the wave. 3. **Substitute Frequency in Terms of Velocity and Wavelength**: - From the wave velocity formula, we can express frequency \( \nu \) as: \[ \nu = \frac{v}{\lambda} \] 4. **Substitute Frequency into the Energy Equation**: - Now, substituting \( \nu \) into the energy equation: \[ E = h \nu = h \left(\frac{v}{\lambda}\right) \] - This simplifies to: \[ E = \frac{hv}{\lambda} \] 5. **Relate Energy and Momentum**: - From the momentum equation, we know: \[ p = \frac{h}{\lambda} \] - Rearranging this gives: \[ h = p \lambda \] 6. **Substitute \( h \) into the Energy Equation**: - Now substitute \( h \) into the energy equation: \[ E = \frac{(p \lambda)v}{\lambda} \] - The \( \lambda \) cancels out: \[ E = pv \] 7. **Solve for Wave Velocity**: - Rearranging the equation \( E = pv \) gives: \[ v = \frac{E}{p} \] 8. **Conclusion**: - Therefore, the wave velocity of light is given by: \[ v = \frac{E}{p} \] ### Final Answer: The wave velocity of light is equal to \( \frac{E}{p} \). ---

To find the wave velocity of light based on the given relationships for the energy and momentum of a photon, we can follow these steps: ### Step-by-Step Solution: 1. **Understand the Given Relationships**: - The energy \( E \) of a photon is given by the equation: \[ E = h \nu ...
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Knowledge Check

  • The energy of a photon of wavelength lambda is

    A
    `hclambda`
    B
    `(hc)/(lambda)`
    C
    `(lambda)/(hc)`
    D
    `lambdah/c`
  • The energy of a photon of wavelength lambda is given by

    A
    `hlambda`
    B
    `chlambda`
    C
    `lambda/"hc"`
    D
    `"hc"/lambda`
  • We may state that the energy E of a photon of frequency v is E =hv, where h is a plank's constant. The momentum p of a photon is p=h//lambda where lambda is the wavelength of the photon. From the above statement one may conclude that the wave velocity of light is equal to

    A
    `3xx10^(8) m//s`
    B
    `E//p`
    C
    `Ep`
    D
    `(E//p)^(2)`
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