Home
Class 12
PHYSICS
The horizontal telegraph wire 100 m long...

The horizontal telegraph wire 100 m long, oriented along magnetic east west falls freely under gravity to the ground with a speed of 20 cm/s. the horizontal component of earth's magnetic field is `4.0xx10^(-5)` tesla. The emf induced in the wire at the instant, the wire strikes the gound is

A

0.4 mV

B

0.2 mV

C

0.8 mV

D

0.6 mV

Text Solution

Verified by Experts

The correct Answer is:
C

`e=B_(H)lv`
`=4xx10^(-5)xx100xx20xx10^(-2)`
`=8xx10^(-4)V`
Promotional Banner

Topper's Solved these Questions

  • ELASTICITY

    NIKITA PUBLICATION|Exercise MCQ|314 Videos
  • ELECTRONS AND PHOTONS

    NIKITA PUBLICATION|Exercise MCQs|162 Videos

Similar Questions

Explore conceptually related problems

A train is moving towards north with a speed of 25 m/s. if the vertical component of the earth's magnetic field is 0.2 xx 10^(-4) T, the emf induced in the axle 1.5 m long is

A horizontal straight wire 20 m long extending from east to west falling with a speed of 5.0 m//s , at right angles to the horizontal component of the earth’s magnetic field 0.30 × 10^(–4) Wb//m^(2) . The instantaneous value of the e.m.f. induced in the wire will be

A metre gauge train is running towards north with a speed of 20 m//s . If the vertical component of earth's magnetic induction is 3 xx 10^(-4) Wb//m^(2) , then the e.m.f. induced at the end of the axle is

A train is moving towards north with a speed of 180 kilometre per hour. If the vertical comonent of the earth's magnetic field is 0.2xx10^(-4) T, the emf induced in the axle 1.5 m longs is -

A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 ms^(-1) at right angle to the horizontal component of the Earth's magnetic field 0.3 xx 10 ^(-4)Wb m^(2) . (a) What is the instantaneous value of the emf induced in the wire? (b) What is the direction of the emf? (c) Which end of the wire is at the higher electrical potential?

A conductor of length 1.0 m falls freely under gravity from a heigth of 10 m so that it cuts the lines of force the horizontal component of earth's magnetic field of 3 xx 10 (-5) Wb m ^(-2) . Find the emf induced in the conductor .

A horizontal conducting rod 10 m long extending from east to west is falling with a speed of 5.0 m//s at right angles to the horizontal component of earth's magnetic field, 0.3 xx 10^(-4) Wb//m^(2) . Find the instantaneous value of e.m.f. induced in the rod.

A wire of length 2 m moves with a speed of 5 m//s perdendicular to a magnetic field of induction 0.1 W//b m^(2) . The e.m.f. induced in the wire is

NIKITA PUBLICATION-ELECTROMAGNETIC INDUCTION-MCQs
  1. The magnetic flux associated with a coil changes from zero to 5xx10^(-...

    Text Solution

    |

  2. A coil having 50 turns and an area of 800 cm^(2) is held with its plan...

    Text Solution

    |

  3. The horizontal telegraph wire 100 m long, oriented along magnetic east...

    Text Solution

    |

  4. A coil of effective area 4m^(2) is placed with its plane perpendicular...

    Text Solution

    |

  5. A coil having an area of 0.4 m^(2) and 100 turns is kept perpendicular...

    Text Solution

    |

  6. A square wire loop with sides 0.5 m is placed with its plane perpendic...

    Text Solution

    |

  7. A meter gauge train runs northwards with a constant speed of 22 m/s on...

    Text Solution

    |

  8. The axle of a railway engine is of length 150 cm. the engine oves with...

    Text Solution

    |

  9. A vertical metal rod of length 1.5 m is at rest in the earth's magneti...

    Text Solution

    |

  10. A vertical metal rod 1 m long performs linear SHM at right angles to B...

    Text Solution

    |

  11. A vertical metal rod of length 1 m moves at right angles to its length...

    Text Solution

    |

  12. A metal rod of length 0.5 m rotates at a uniform angular speed about o...

    Text Solution

    |

  13. A coil of 500 turns and mean radius 10 cm makes 3000 rotations per min...

    Text Solution

    |

  14. A coil of 1000 turns each of area 1.2m^(2) is rotating about an axis i...

    Text Solution

    |

  15. An alternating emf, e=200 sin omegat is applied to a lamp, whose filam...

    Text Solution

    |

  16. When an alternating emf, e=300 sin 100pit volt is applied across a bul...

    Text Solution

    |

  17. An alternating emf of peak value 350 V is applied across an a.c. ammet...

    Text Solution

    |

  18. A circular coil of 50 turns an diameter 24 cm is rotated continuously ...

    Text Solution

    |

  19. The self inductance of a circuit ini which an emf of 10 V is induced w...

    Text Solution

    |

  20. The mutual inductance of a pair of a coil is 0.75 H. if the current in...

    Text Solution

    |