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प्रश्न
In an accelerator experiment on high-energy collisions of electrons with positrons, a certain event is interpreted as annihilation of an electron-positron pair of total energy 10.2 BeV into two γ-rays of equal energy. What is the wavelength associated with each γ-ray? (1BeV = 109 eV)
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उत्तर
Total energy of two γ-rays:
E = 10. 2 BeV
= 10.2 × 109 eV
= 10.2 × 109 × 1.6 × 10−10 J
Hence, the energy of each γ-ray:
`"E'" = "E"/2`
= `(10.2 xx 1.6 xx 10^(-10))/2`
= 8.16 × 10−10 J
Planck’s constant, h = 6.626 × 10−34 Js
Speed of light, c = 3 × 108 m/s
Energy is related to wavelength as:
`"E'" = "hc"/lambda`
∴ `lambda= "hc"/"E'"`
= `(6.626 xx 10^(-34) xx 3 xx 10^8)/(8.16 xx 10^(-10))`
= 2.436 × 10−16 m
Therefore, the wavelength associated with each γ-ray is 2.436 × 10−16 m.
संबंधित प्रश्न
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(Use h = 6.63 × 10-34J-s = 4.14 × 10-15 eV-s, c = 3 × 108 m/s and me = 9.1 × 10-31kg)
Use Einstein's photoelectric equation to show how from this graph,
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Each photon has the same speed but different ______.
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Surface B: photoemission occurs but the photoelectrons have zero kinetic energy.
Surface C: photo emission occurs and photoelectrons have some kinetic energy.
Using Einstein’s photo-electric equation, explain the three observations.
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If c is the velocity of light in free space, the correct statements about photon among the following are:
- The energy of a photon is E = hv.
- The velocity of a photon is c.
- The momentum of a photon, ρ = `(h v)/c`
- In a photon-electron collision, both total energy and total momentum are conserved.
- Photon possesses positive charge.
Choose the correct answer from the options given below:
