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A source of light is placed above a sphe...

A source of light is placed above a sphere of radius `10cm`. How many photoelectrons must be emitted by the sphere before emission of photoelectrons stop? The energy of incident photon is `4.2eV` and the work function of the metal is `1.5eV`.

A

`2.08 xx 10^(18)`

B

`1.875 xx 10^(8)`

C

`2.88 xx 10^(18)`

D

4 xx 10^(19)`

Text Solution

Verified by Experts

Stopping poetntial energy = `eV_(0) = E - omega`
`V_(0) = (E-omega)/€=(9 xx 10^(9)ne)/( e) , n = "no of electros"`
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NARAYNA-DUAL NATURE OF RADIATION AND MATTER-EXERCISE - 4
  1. When a surface 1 cm thick is illuminated with light of wavelength lamb...

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  2. A photon of energy 2.5 eV and wavelength lambda falls on a metal surfa...

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  3. A source of light is placed above a sphere of radius 10cm. How many ph...

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  4. From the above figure the values of stopping potentials for M(1) and M...

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  5. For certain photosensitive material, a stopping potential of 3.0 V is ...

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  6. Light of wavelength 180 nm ejects photoelectrons from a plate of met...

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  7. Light described at a place by the equation E = (100V//m) xx [sin (5 xx...

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  8. The electric field associated with a light wave is given by E=E(0)sin[...

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  9. An electron of mass m and charge e initially at rest gets accelerated ...

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  10. A praticle of mass M at rest decays into two particle of masses m1 and...

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  11. A photon and an electron have equal energy E . lambda("photon")//lambd...

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  12. When a monochromatic point source of light is at a distance of 0.2 m...

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  13. An X-ray tube is operated at 50 kV and 20 m A. The target material of ...

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  14. The potential energy of a particle of mass m is given by V(x) = E0 w...

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  15. According to Einstein's photoelectric equation , the graph between the...

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  16. Which of the following figure represents the variation of particle mom...

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  17. The de Broglie wave present in fifth Bohr orbit is:

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  18. The graph shown in figure show the variation of photoelectric current ...

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  19. The anode voltage of photocellis kept fixed. The wavelength lambda of ...

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  20. The two lines A and B shown in figure are the graphs of the de Broglie...

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