Home
Class 10
PHYSICS
Why are filaments of incandescent lamps ...

Why are filaments of incandescent lamps made of thin tungsten wire ?

Text Solution

Verified by Experts

Tungsten has low resistivity and as such only a thin wire filament will high resistance necessary to produce large amount of heat to light the bulb brilliantly. Further, tungsten has very high melting point `(3300 K)` and as such the filament will not burn at the high temperature `(2400 K)` at which it becomes incandescent.
Promotional Banner

Topper's Solved these Questions

  • ELECTRICITY

    PRADEEP|Exercise (Additional)Long Answer|4 Videos
  • ELECTRICITY

    PRADEEP|Exercise Based On Practical|10 Videos
  • ELECTRICITY

    PRADEEP|Exercise (Additional)Very Short Answer|47 Videos
  • MAGNETIC EFFECTS OF ELECTRIC CURRENT

    PRADEEP|Exercise Mock Test|21 Videos

Similar Questions

Explore conceptually related problems

The resistance of an incandescent lamp is

The filament of an electric bulb is made of tungsten.

The filament of an electric bulb is made of

The filament of an electric bulb is made of a thin wire of :

Determine the surface area of the filament of a 100W incandescent lamp radiating out its labelled power at 3000K. Given sigam = 5.7 xx 10^(-8)Wm^(-2)K^(-4) , and emissivity epsilon of the material of the filament = 0.3.

Explain the following : (a) Why is tungsten used almost axclusively for filament of incandescent lamp ? (b) Why are the conductors of electric heating devices, such as toaster and electric irons, made of an alloy rather than a pure metal ? ( c) Why is the series arrangement not used for domestic circuits ? (d) How does the resistance of a wire vary with its cross-sectional area ? (e ) Why are copper and aluminimum wires usually employed for electricity transmission.

Incandescent Electric Lamp

What will be the surface area of a filament of 200 W incandescent lamp at 2000 K. sigma = 5.67 xx 10^(-8) Wm^(-2) K^(-4) and emissivity e = 0.3?

PRADEEP-ELECTRICITY-(Additional)Short Answer
  1. Under what conditions is Ohm's law applicable ?

    Text Solution

    |

  2. Two wires are of the same material but of different lengths and areas ...

    Text Solution

    |

  3. Why are filaments of incandescent lamps made of thin tungsten wire ?

    Text Solution

    |

  4. Why is nichrome used as a heating element ?

    Text Solution

    |

  5. What is the difference between a resistor and resistance ?

    Text Solution

    |

  6. Why are constantan and manganin used for making standard resistances ?

    Text Solution

    |

  7. Why is lead-tin alloy used for making fuse ?

    Text Solution

    |

  8. What are superconductors ?

    Text Solution

    |

  9. (a) What is common between charge and mass ? (b) We know that mass v...

    Text Solution

    |

  10. (a) What are two physical quantities to which electric potential is an...

    Text Solution

    |

  11. (a) What do you mean by the term load in an electric circuit ? (b) W...

    Text Solution

    |

  12. (a) Which is more conducting : silver or gold ? (b) Which is a bette...

    Text Solution

    |

  13. (a) Of which material is a fuse-wire made of ? (b) Of which material...

    Text Solution

    |

  14. (a) Whose resistivity increases more with temperature : of an alloy or...

    Text Solution

    |

  15. A wire having a resistance of 18 Omega is cut into three equal parts. ...

    Text Solution

    |

  16. What is the ratio of equivalent resistance of series combination of n ...

    Text Solution

    |

  17. A given wire is stretched to double its length. How will its resistanc...

    Text Solution

    |

  18. A wire of 3 Omega resistance and 10 cm length is stretched to 30 cm le...

    Text Solution

    |

  19. (a) When is the pd for all the resistors in a circuit the same and is ...

    Text Solution

    |

  20. (a) How does the current divide itself in a parallel combination of re...

    Text Solution

    |