Home
Class 12
PHYSICS
A transformer is used to light a 140 W, ...

A transformer is used to light a 140 W, 24 V lamp from 240 V AC mains. The current in mains cable is 0.7 A, find the efficiency of transformer.

A

`63.8%`

B

`84%`

C

`83.3%`

D

`48%`

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • NEET MOCK TEST 14

    NTA MOCK TESTS|Exercise PHYSICS|45 Videos
  • NEET MOCK TEST 16

    NTA MOCK TESTS|Exercise PHYSICS|45 Videos

Similar Questions

Explore conceptually related problems

A transformer is used to light a 100 W and 110 V lamp from a 220V mains. If the main current is 0.5 A , the Efficiency of the transformer is approximately:

NTA MOCK TESTS-NEET MOCK TEST 15-PHYSICS
  1. A current I=20sin(100pit)A is passed in the first coil, which induces ...

    Text Solution

    |

  2. A uniform magnetic field exists in region given by vec(B) = 3 hat(i) +...

    Text Solution

    |

  3. A transformer is used to light a 140 W, 24 V lamp from 240 V AC mains....

    Text Solution

    |

  4. The current in an LCR circuit is given by I=20sin (100pi t+(pi)/(6))A....

    Text Solution

    |

  5. The time required for a 50Hz alternating current to increase from zero...

    Text Solution

    |

  6. The focal length of a simple convex lens used as a magnifier is 10 cm....

    Text Solution

    |

  7. In Young's double slit experiment, the ratio of maximum and minimum in...

    Text Solution

    |

  8. The plane surface of a plano-convex lens of focal length f is silvered...

    Text Solution

    |

  9. What is value of current I in given circuit

    Text Solution

    |

  10. The figure gives a system of logic gates. From the study of the truth ...

    Text Solution

    |

  11. In an excited state of hydrogen like atom an electron has total energy...

    Text Solution

    |

  12. The energies of energy levels A, B and C for a given atom are in the s...

    Text Solution

    |

  13. If the overbridge is concave instead of being convex, the thrust on th...

    Text Solution

    |

  14. A particle is moving with a constant speed along a straight line path....

    Text Solution

    |

  15. Which of the following statements is not true

    Text Solution

    |

  16. If vecA=4hati-3hatj and vecB=6hati+8hatj then magnitude and direction ...

    Text Solution

    |

  17. The random error in the arithmetic mean of 100 observations is x, then...

    Text Solution

    |

  18. 50 g ice at 0^(@)C in kept in an insulating vessel and 50 g water at 1...

    Text Solution

    |

  19. Distribution of energy in the spectrum of a black body can be correctl...

    Text Solution

    |

  20. Air is bad conductor of heat or partly conducts heat, still vacuum is ...

    Text Solution

    |