Home
Class 12
PHYSICS
Determine the percentage by which the il...

Determine the percentage by which the illumination of a lamp will decrease if the current drops by 20%.

Promotional Banner

Topper's Solved these Questions

  • ELECTROSTATIC FORCES, CHARGES AND FIELDS

    SL ARORA|Exercise Problems For Self Practice|1 Videos

  • MAGNETIC EFFECTS OF CURRENT

    SL ARORA|Exercise TYPE C|4 Videos

Similar Questions

Explore conceptually related problems

By what percentage will the illimination of the lamp decrease if the current drops by 20% ?

Statement I : If the current of a lamp increases by 20 % , the percentage increases in the illlumination of the lamp is 40% . Statement II : Illumination of the lamp is directly proportional to the square of the current through the lamp.

if the electrc current in a lamp decreases by 5% then the power output decreases by

If R is the radius of the Earth then the height above the Earth's surface at which the acceleration due to gravity decreases by 20% is

If the price of petrol is increased by 20%,by what percentage should the consumption be decreased by the consumer, if the expenditure on petrol remains unchanged?

By what percentage should the pressure of a given mass of a gas be increased so as to decrease its volume by 20% at a constant temperature?

The price of oil is increased by 20%. However, the expenditure on it increases by 15%. What is the percentage increase or decrease in the consumption of oil?

SL ARORA-HEATING EFFECT OF CURRENT-All Questions
  1. A heater coil is rated 100W,200V. It is cut into two identical parts. ...

    Text Solution

    |

  2. An electric bulb is marked 100W, 230V. If the supply voltage drops to ...

    Text Solution

    |

  3. Determine the percentage by which the illumination of a lamp will decr...

    Text Solution

    |

  4. An electric bulb rated for 500W at 100V is used in circuit having 200V...

    Text Solution

    |

  5. The maximum power rating of a 20Omega resistor is 2.0kW. (that is this...

    Text Solution

    |

  6. A 25W and 100W bulbs are joined in series and connected to the mains. ...

    Text Solution

    |

  7. An electric heater and an electric bulb are rated 500W. 220V and 100W,...

    Text Solution

    |

  8. Two heatere are marked 200V, 300W and 200V, 600W. If the heaters are c...

    Text Solution

    |

  9. Three identical resistors, each of resistance R, when connected in ser...

    Text Solution

    |

  10. In the circuit shown in Fig.6.1, each of the three resistors of 4Omega...

    Text Solution

    |

  11. Find the heat produced per minute in each of the resistors shown in fi...

    Text Solution

    |

  12. A 2H.P. electric motor working on 220V mains runs for 6hours a day. If...

    Text Solution

    |

  13. A house is fitted with 20lamps of 60W each, 10fans consuming 0.5A each...

    Text Solution

    |

  14. There are two electric bulbs rated 60W. 110V and 100W, 110V. They are ...

    Text Solution

    |

  15. Twenty one electric bulbs are connected in series with the mains of a ...

    Text Solution

    |

  16. Find the resistance of 240 V - 200 watt electric bulb when glowing. If...

    Text Solution

    |

  17. A thin metallic wire of resistance 100Omega is immersed in a calorimet...

    Text Solution

    |

  18. A copper electric kettle weighing 1000 g contains 900g of water at 20^...

    Text Solution

    |

  19. A coil of enamelled copper wire of resistance 50Omega is embedded in a...

    Text Solution

    |

  20. The heater coil of an elecric kettle is rated at 2000W,200V, How much ...

    Text Solution

    |