Home
Class 12
PHYSICS
Surface of certain metal is first illumi...

Surface of certain metal is first illuminated with light of wavelength `lambda_(1)=350` nm and then, by light of wavelength `lambda_(2)=540` nm. It is found that the maximum speed of the photo electrons in the two cases differ by a factor of 2. The work function of the metal (in eV) is close to :
(Energy of photon `=(1240)/(lambda("in nm"))Ev`

A

2.5

B

1.8

C

5.6

D

1.4

Text Solution

Verified by Experts

The correct Answer is:
B
`1240/540 -phi=kimplies2.296-phi=k`……..i
`1240/350-phi=4kimplies3.543-phi=4k`….ii
Solving I and ii `k=k0.416, phi=1.88eV`
Promotional Banner

Topper's Solved these Questions

  • REVISION TEST-15 JEE - 2020

    VMC MODULES ENGLISH|Exercise PHYSICS|25 Videos

  • ROTATIONAL MOTION

    VMC MODULES ENGLISH|Exercise JEE Advanced (Archive) (True/False Type)|3 Videos

Similar Questions

Explore conceptually related problems

Lights of wavelenths lambda_(1)=340nm and lambda_(2)=540nm are incident on a metallic surface. If the ratio of the maximum speeds of electrons ejected is 2, the work function of the metal is

When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm, the maximum kinetic energy of the photo electrons becomes three times larger. The work function of the metal is close to :

The surface of a metal is illuminated alternately with photons of energies E_(1) = 4 eV and E_(2) = 2.5 eV respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is 2. The work function of the metal in (eV) is ________.

A light of wavelength 600 nm is incident on a metal surface. When light of wavelength 400 nm is incident, the maximum kinetic energy of the emitted photoelectrons is doubled. The work function of the metals is

Light of wavelength 4000A∘ is incident on a metal surface. The maximum kinetic energy of emitted photoelectron is 2 eV. What is the work function of the metal surface?

When a metal surface is illuminated by light wavelengths 400 nm and 250 nm , the maximum velocities of the photoelectrons ejected are upsilon and 2 v respectively . The work function of the metal is ( h = "Planck's constant" , c = "velocity of light in air" )

Maximum kinetic energy of photoelectrons emitted from a metal surface, when light of wavelength lambda is incident on it, is 1 eV. When a light of wavelength lambda/3 is incident on the surfaces, maximum kinetic energy becomes 4 times. The work function of the metal is

When a metalic surface is illuminated with light of wavelength lambda, the stopping potential is V. the same surface is illuminated by light of wavelength 2lambda the stopping potential is (V)/(3) The thershold waelength for the surface is

A photoelectric surface is illuminated successively by monochromatic light of wavelength lambda and (lambda)/(2) . If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times than in the first case , the work function of the surface of the material is ( h = Plank's constant , c = speed of light )

A photoelectric surface is illuminated successively by monochromatic light of wavelength lambda and (lambda)/(2) . If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times than in the first case , the work function of the surface of the material is ( h = Plank's constant , c = speed of light )

VMC MODULES ENGLISH-REVISION TEST-2 JEE-PHYSICS
  1. A plane electromagnetic wave of frequency 50 MHz travels in free space...

    Text Solution

    |

  2. A heavy ball is mass M is suspended from the ceiling of a car by a lig...

    Text Solution

    |

  3. A parallel plate capacitor is made of two square plates of side 'a' , ...

    Text Solution

    |

  4. A rod, of length L at room tempera ture and uniform area of cross sect...

    Text Solution

    |

  5. Surface of certain metal is first illuminated with light of wavelength...

    Text Solution

    |

  6. A particle is moving with velocity vecv=K(y hat i+x hat j), where K is...

    Text Solution

    |

  7. Temperature difference of 120^(@)C is maintained between two ends of a...

    Text Solution

    |

  8. A resistance is shown in the figure. Its value and tolerance are given...

    Text Solution

    |

  9. Mobility of electrons in a semiconductor is defined as the ratio of th...

    Text Solution

    |

  10. Two coherent sources produce waves of different intensities which inte...

    Text Solution

    |

  11. A copper wire is stretched to make it 0.5% longer. The percentage chan...

    Text Solution

    |

  12. A sample of radioactive material A, that has an activity of 10 mCi(1 C...

    Text Solution

    |

  13. Two masses m and (m)/(2) are connected at the two ends of a massless r...

    Text Solution

    |

  14. A convex lens is put 10 cm from a light source and it makes a sharp im...

    Text Solution

    |

  15. A block of mass 10 kg is kept on a rough inclined plane as shown in th...

    Text Solution

    |

  16. Drift speed of electrons, when 1.5 A of current flows in a copper wire...

    Text Solution

    |

  17. Three blocks A, B and C are lying on a smooth horizontal surface, as s...

    Text Solution

    |

  18. For a uniformly charged ring of radius R, the electric field on its ex...

    Text Solution

    |

  19. A bar magnet is demagnetized by inserting it inside a solenoid of leng...

    Text Solution

    |

  20. Consider a tank made of glass (refractive index 1.5) with a thick bott...

    Text Solution

    |