Home
Class 12
PHYSICS
An electric iron of resistance 20 Omega ...

An electric iron of resistance `20 Omega` takes a current of `5 A`. Calculate the heat developed in `30 s`.

A

`5 kJ`

B

`10kJ`

C

`15kJ`

D

`20kJ`

Text Solution

Verified by Experts

The correct Answer is:
C
Required heat would be 15 kJ
Promotional Banner

Topper's Solved these Questions

  • Heat & Thermodynamics

    NDA PREVIOUS YEARS|Exercise Physics|64 Videos

Similar Questions

Explore conceptually related problems

(a) what is menat by the heating effect of current ? State three factors on which the heat produced in a wire by an electric current depends. (b) Explain why, through the heating element of an electric heater glows, but its connecting cord does not l glow. ( c) An electric geyser of resistance 20 Omega takes a current of 5 A. calculate the heat produced in 2 minutes. (d) Name the commercial unit of electric energy. How many joules are equal to this unit ?

(a) Write down the formula for the heat produced when a current I is passed through a resistor R for time t. (b) An electric iron of resistance 20 ohms draws a current of 5 amperes. Calculate the heat produced in 30 seconds.

An electric bulb of resistance 400 Omega , draws a current of 0.5 A . Calculate the power of the bulb and the potential difference at its ends.

An electric heater of resistance 8 Omega draws 15 A from the service mains for 2 hours. Calculate the rate at which heat is developed in the heater.

A galvanometer of resistance 30 Omega shows a full scale deflection for a current of 2 mA. Calculate the value of resistance required to convert it into a voltmeter of range 0-5 volt.

NDA PREVIOUS YEARS-ELECTRICITY & MAGNETISM -MCQ
  1. Net charge in a current-carrying conductor is

    Text Solution

    |

  2. Which one of the following is the resistance that must be placed paral...

    Text Solution

    |

  3. An electric iron of resistance 20 Omega takes a current of 5 A. Calcul...

    Text Solution

    |

  4. A house, served by a 220 V supply line, is protected by a 9A fuse. Wha...

    Text Solution

    |

  5. The effective resistance of three equal resistances, each of resistanc...

    Text Solution

    |

  6. The magnetic lines of force due to the bar magnet

    Text Solution

    |

  7. The specific resistance of a conducting wire depends upon

    Text Solution

    |

  8. Which one of the statement given below is not correct?

    Text Solution

    |

  9. How many sixty watt (60 W) bulbs may be safely used in a 240-V supply ...

    Text Solution

    |

  10. Magnetism of a bar magnet can be destroyed if it is (I) kept in the ...

    Text Solution

    |

  11. Capacity of a parallel plate condenser can be doubled by (I) doublin...

    Text Solution

    |

  12. If two conducting spheres are separately charged and then brought in c...

    Text Solution

    |

  13. Two pieces of metallic wire having equal lengths and equal volume plac...

    Text Solution

    |

  14. If a heater coil is cut into two equal parts and only one part is used...

    Text Solution

    |

  15. The direction of magnetic field at a point due to an infinitely long w...

    Text Solution

    |

  16. A hollow metal ball carrying an electric charge produces no electric f...

    Text Solution

    |

  17. The material used for electric fuse is an alloy of tin and lead. This ...

    Text Solution

    |

  18. The lines of force of uniform magnetic field

    Text Solution

    |

  19. If the electrical resistance of a typical substance suddenly drops to ...

    Text Solution

    |

  20. Magnets attract magnetic substances are iron, nickel, cobalt, etc. The...

    Text Solution

    |