Home
Class 12
PHYSICS
The electric bulb have tungsten filament...

The electric bulb have tungsten filaments of same length. If one of them gives 60 W and other 100 W, then

A

`100 W` bulb has thicker filament

B

`60 W` bulb has thicker filament

C

both filaments are of same thickness

D

it is not possible to get different wattages unless the lengths are different

Text Solution

Verified by Experts

The correct Answer is:
A

`P = V^(2)//R` . If `P` is more , `R` is less . `R = rho l // a`. For less `R`, a is more . So the `100 W` bulb has thicker element .
Promotional Banner

Topper's Solved these Questions

  • HEATING EFFECT OF CURRENT

    CENGAGE PHYSICS ENGLISH|Exercise Multiple Correct|5 Videos
  • HEATING EFFECT OF CURRENT

    CENGAGE PHYSICS ENGLISH|Exercise Assertion - Reasoning|6 Videos
  • HEATING EFFECT OF CURRENT

    CENGAGE PHYSICS ENGLISH|Exercise Subjective|8 Videos
  • GEOMETRICAL OPTICS

    CENGAGE PHYSICS ENGLISH|Exercise Integer Type|4 Videos
  • INDUCTANCE

    CENGAGE PHYSICS ENGLISH|Exercise Concept Based|8 Videos

Similar Questions

Explore conceptually related problems

Two electric bulbs have tungsten filament of same length. If one of them gives 60 W and the other 100 W , then

The tungsten filaments of two electric bulbs are of the same length. If one of them gives 25 W power and the other 60 W power, then

Two electric bulbs , rated for the same voltage , have powers of 200 W and 100 W , respectively. If their resistances are r_(1) and r_(2) , respectively , then

A 100W bulb has tungsten filament of total length 1.0m and raidius 4xx10^(-5)m . The emiswsivity of the filament is 0.8 and sigma=6.0xx10^(-8)Wm^(-2)K^(-4) . Calculate the temperature of the filament when the bulb is oprating at correct wattage.

Two 100W bulbs one having the tungsten filament and the other carbon filament are joined in series with a power supply. How will their brightness change as time passes on .

The operating temperature of an in candescent bulb (with tungsten filament) of power 60 W is 3000 K. If the surface area of the filament be 25 mm^2 , find its emissivity e.

The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use?

An electric bulb is marked 200V, 100W. Calculate electrical resistances of its filament. If five such bulbs are connected in series to a 200V supply, how much current will flow through them?

Two electric bulbs one, if 200 V-40 W and other 200 V-100 W are connected in series to a 200 V line, then the potential drop across

In an electrical circuit three incandescent bulbs A,B and C of rating 40 W, 60 W and 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness ?

CENGAGE PHYSICS ENGLISH-HEATING EFFECT OF CURRENT-Single Correct
  1. An electric bulb rated for 500 W at 100 V is used in a circuit having ...

    Text Solution

    |

  2. A 1^(@) C rise in temperature is observed in a conductor by passing a ...

    Text Solution

    |

  3. The electric bulb have tungsten filaments of same length. If one of th...

    Text Solution

    |

  4. n identical light bulbs, each designed to draw P power from a certain ...

    Text Solution

    |

  5. How many calories of heat will be produced approximately in 210 watt ...

    Text Solution

    |

  6. A constant voltage is applied between two ends of a metallic wire if t...

    Text Solution

    |

  7. The power rating of an electric motor that draws a current of 3.75 A, ...

    Text Solution

    |

  8. A cable of resistance 10 Omega carries electric power from a generator...

    Text Solution

    |

  9. a cable of resistance 10 ohm carries electric power from a generator p...

    Text Solution

    |

  10. The heat generated through 4 Omega and 9 Omega resistances separately ...

    Text Solution

    |

  11. If the length of the filament of a heater is reduced by 10%, the power...

    Text Solution

    |

  12. A 2k W heater used for 1 h every day consumes the following electrica...

    Text Solution

    |

  13. Two cells, each of emf E and internal resistance r are connected in pa...

    Text Solution

    |

  14. A constant voltage is applied between the two ends of a uniform metall...

    Text Solution

    |

  15. A given resistor cannot carry currents exceeding 20 A, without exceedi...

    Text Solution

    |

  16. A wire when connected to 220 V mains supply has power dissipation P(1)...

    Text Solution

    |

  17. A 220 volt, 1000 watt bulb is connected across a 110 volt mains supply...

    Text Solution

    |

  18. A heater coil is cut into two equal parts and only one part is now use...

    Text Solution

    |

  19. Three 10 Omega , 2 W resistors are connected as in Fig. 7.34. The maxi...

    Text Solution

    |

  20. A torch bulb rated 4.5 W, 1.5 V is connected as shown in Fig. 7.35. Th...

    Text Solution

    |