Home
Class 12
PHYSICS
The operating temperature of the filamen...

The operating temperature of the filament of lamp is `2000^(@) C`. The temperature coefficient of the material of the filament is `0.005^(@) C^(-1)`. If the atmospheric temperature is `0^(@) C`, then the current in the `100 W - 200 V` lamp when it is switched on is nearest to

A

`2.5 A`

B

`3.5 A`

C

`4.5 A`

D

`5.5 A`

Text Solution

Verified by Experts

The correct Answer is:
D
`R_(200) = ( 200 xx 200)/( 100) = 400 Omega`
So `400 = R_(0) [ 1 + 0.005 xx 2000]`
or `(R_(0)) = ( 400 )/(11) Omega ~~ 36 Omega`
Hence , current
`I = ( 200) /( R_(0)) = 5.5 A`
Doubtnut Promotions Banner Mobile Dark
|

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

The temperature coefficient of resistance of the material of a wire is 0.00125^(@)C^(-1) . Its resistance at 27^(@)C is 1 Omega . At what temperature will its resistance be 2 Omega ?

The temperature coefficient of resistance of a wire is 0.00145^(@)C^(-1) . At 100^(@)C its resistance is 2Omega . At what temperature the resistance of the wire be 3Omega ?

Knowledge Check

  • The temperature coefficient of resistance of wire is 0.001259^(@)C^(-1) . If resistance is 1Omega at 300 K, then 2Omega will be at:

    A
    1400 K
    B
    1100 K
    C
    1127 J
    D
    1154 K

  • The resistance of a coi is 4.2Omega at 100^(@)C and the temperature coefficient of resistance of its material is (0.004)/(.^(@)C) . Its resistance at 0^(@)C is

    A
    `6.5Omega`
    B
    `5Omega`
    C
    `3Omega`
    D
    `2.5Omega`

  • The temperature coefficient of resistance for a wire is 0.00125^(@)C^(-1) . At 300 K its resistance is 1Omega . The temperature at which the resistance becomes 2Omega is

    A
    450 K
    B
    1127 K
    C
    454 K
    D
    900 K

    • Similar Questions

    Explore conceptually related problems

    The temperature of the filament in a light bulb is about 1800^(@)C , what will it be on Fahrenheit scale?

    The temperature coefficient of a resistance wire is 0.00 12^(@)C^(-1) . At 300 K, its resistance is 1 Omega . At what temperature the resistance of the wire will be 2 Omega ?

    A comon flashlight bulb is rated 0.30A and 2.7V (the values of the current and voltage under operating conditions.) If the resistance of the tungsten bulb filament at room temperature 20^(@)C is 1.0Omega and its temperature coefficient of resistivity is 4.0 xx 10^(-3)C^(-1) , then find the temperature in centigrade of the filament when the bulb is on. (Consider the variationi of resistance to be linear with temperature.)

    Temperature coefficient of resistance of a wire at 0^(@)C is 0.00125^(@)C^(-1) . At 25^(@)C its resistance is 1 Omega . The resitance of the wire will be 1.2 Omega at

    The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use?

    Home
    Profile