Home
Class 12
PHYSICS
A wire when connected to 220 V mains sup...

A wire when connected to 220 V mains supply has power dissipation `P_1`. Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is `P_2`. Then `P_2: P_1` is

A

`1`

B

`4`

C

`2`

D

`3`

Text Solution

Verified by Experts

The correct Answer is:
B
`P = V^(2)// R`. `R` is reduced by a factor of `4` . So `P` is increased by a factor `4`.
Promotional Banner

Topper's Solved these Questions

  • HEATING EFFECT OF CURRENT

    CENGAGE PHYSICS|Exercise Multiple Correct|5 Videos

  • HEATING EFFECT OF CURRENT

    CENGAGE PHYSICS|Exercise Assertion - Reasoning|6 Videos

  • HEATING EFFECT OF CURRENT

    CENGAGE PHYSICS|Exercise Subjective|8 Videos

  • GRAVITATION

    CENGAGE PHYSICS|Exercise Question Bank|39 Videos

  • INDUCTANCE

    CENGAGE PHYSICS|Exercise Concept Based|9 Videos

Similar Questions

Explore conceptually related problems

A wire when connected to 220 V mains supply has power dissipation P_(1) . Now, the wire is cut into two equal pieces which are connected in parallel to same supply. Power dissipation in this case is P_(2) . Then, P_(1) : P_(2) is

A wire when connected to 220V mains sapply power dissipation P_(1) Now the wire is cut into two equal pieces which are connected in parallel to the same apply power dissipation in this case is P_(2) then P_(1) : P_(2) is

A resistor R has power of dissipation P with cell voltage E . The resistor is cut in equal parts and all parts are connected in parallel with same cell. The new power dissipation is

A heater coil connected to a supply of a 220 V is dissipating some power . P_(1) The coil is cut into half and the two halves are connected in parallel. The heater now dissipates a power . P_(2) Theratio of power P_(1) : P_(2) is

Power generated across a uniform wire connected across a supply is H . If the wire is cut into n equal parts and all the parts are connected in parallel across the same supply, the total power generated in the wire is

Two resistors whose value are in ratio 2 : 1 are connected in parallel with one cell. Then ratio of power dissipated is

The power dissipated by a light bulb with 4 ohm resistance when connected in parallel to 12V battery is

A heater coil c onnected across a give potential difference has power P . Now , the coil is cut into two equal halves and joined in parallel . Across the same potential difference, this combination has power

Three equal resistors connected in series across a source emf together dissipate 4 watt.If the same resistors are connected in parallel across the same emf the power dissipate will be

3 identical bulbs are connected in series and these together dissipate a power P . If now the bulbs are connected in parallel, then the power dissipated will be

CENGAGE PHYSICS-HEATING EFFECT OF CURRENT-Single Correct
  1. A constant voltage is applied between the two ends of a uniform metall...

    Text Solution

    |

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

    Text Solution

    |

  3. A wire when connected to 220 V mains supply has power dissipation P1. ...

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

  8. A heater is designed to operate with a power of 1000W in a 100 V line....

    Text Solution

    |

  9. The supply voltage to room is 120 V. The resistance of the lead wires ...

    Text Solution

    |

  10. Figure 7.37 shows a network of three resistances. When some potential...

    Text Solution

    |

  11. Resistors P , Q , and R in the circuit have equal resistances. If the ...

    Text Solution

    |

  12. Three bulbs of 40 W , 60 W and 100 W are connected in series with a 24...

    Text Solution

    |

  13. In the circuit shown in fig the heat produced in the 5 ohm resistor du...

    Text Solution

    |

  14. A battery of internal resistance 4Omega is connected to the network of...

    Text Solution

    |

  15. Four resistances carrying a current shown in Fig. 7.41 are immersed in...

    Text Solution

    |

  16. The three resistance of equal value are arranged in the different comb...

    Text Solution

    |

  17. An ideal gas is filled in a closed rigid and thermally insulated conta...

    Text Solution

    |

  18. The resistance in which the maximum heat is produced is given by ( Fig...

    Text Solution

    |

  19. The resistance of hot tungsten filament is about 10 times the cold res...

    Text Solution

    |

  20. The resistance of the filament of a lamp increases with the increase i...

    Text Solution

    |