Home
Class 12
PHYSICS
If voltage across a bulb rated 220 volt-...

If voltage across a bulb rated 220 volt-100 watt drops by `2.5 %` of its value, the percentage of the rated value by which the power would decrease is

A

0.05

B

0.1

C

0.2

D

`2.5%`

Text Solution

Verified by Experts

The correct Answer is:
A
Power `P=(V^(2))/(R )`
For small variation, `(Delta P)/(P)xx100%=(2xxDelta V)/(V)xx100%` therefore power would decrease by 5%
Promotional Banner

Topper's Solved these Questions

  • NEET

    NEET PREVIOUS YEAR (YEARWISE + CHAPTERWISE)|Exercise QUESTION|95 Videos

  • MOTION IN TWO AND THREE DIMENSION

    NEET PREVIOUS YEAR (YEARWISE + CHAPTERWISE)|Exercise All Questions|47 Videos

  • NEET 2020

    NEET PREVIOUS YEAR (YEARWISE + CHAPTERWISE)|Exercise All Questions|45 Videos

Similar Questions

Explore conceptually related problems

If voltage across a bulb rated 22 volt 100 watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is

If voltage across a bulb rated 220volts 100watts drops by 2.5% of its rated value,the percentage of the rated value by which the power would decrease is :-

If voltage across a bulb rated 220 V, 160 W drops by 3% of its rated value, the percentage of the rated value by which the power would decrease is

If voltage across a bulb rated 220 V – 100 W drops by 2.5% of its rated value, the percentage of the rated value by which the fractional power would decrease, is -

An electric bulb is rated 220 volt - 100 watt. The power consumed by it when operated on 110 volt will be

The voltage across a bulb is decreased by 2%. Assuming that the resistance of the filament remains unchanged, the power of the bulb will

The voltage across an electric bulb is decreased by 2% . Assuming that the resistance of the filament remains same, the power consumed will

If the current in a electric bulb drops by 2% then the power decreases by

NEET PREVIOUS YEAR (YEARWISE + CHAPTERWISE)-NEET-MCQ
  1. In an electrical circuit R,L,C and an AC voltage source are all connec...

    Text Solution

    |

  2. A ring is made of a wire having a resistance R(0) = 12Omega . Find the...

    Text Solution

    |

  3. If voltage across a bulb rated 220 volt-100 watt drops by 2.5 % of its...

    Text Solution

    |

  4. In the circuit shown the cells A and B have negligible resistance. For...

    Text Solution

    |

  5. The electric field associted with an electromagnetic wave in vacuum is...

    Text Solution

    |

  6. What is the flux through a cube of side 'a' if a point charge of q is ...

    Text Solution

    |

  7. An electric dipole moment p is placed in an electric field of intensit...

    Text Solution

    |

  8. Four point charges -Q, -q, 2q and 2Q are placed, one at each corner of...

    Text Solution

    |

  9. A compose needle which is allowed to move in a horizontal plane is tak...

    Text Solution

    |

  10. A milli-voltmeter of 25 milli-volt range is to be converted into an am...

    Text Solution

    |

  11. Two similar coils of radius R are lying concentriclaly with their pl...

    Text Solution

    |

  12. An alternating electric field, of frequency v, is applied across the d...

    Text Solution

    |

  13. The magnifying power of a telescope is 9. When it is adjusted for para...

    Text Solution

    |

  14. A ray of light is incident at small angle I on the surface of prism of...

    Text Solution

    |

  15. A concave mirrorr of focal length f(1) is placed at a distance of d fr...

    Text Solution

    |

  16. When a biconvex lens of glass having refractive index 1.47 is dipped i...

    Text Solution

    |

  17. A alpha -parhticle moves in a circular path of radius 0.83 cm in th...

    Text Solution

    |

  18. Monochromatic radiation emitted when electron on hydrogen atom jumps f...

    Text Solution

    |

  19. A modern 200 W sodium street lamp emits yellow light of wavelength 0.6...

    Text Solution

    |

  20. Electron in hydrogen atom first jumps from third excited state to seco...

    Text Solution

    |