Home
Class 12
PHYSICS
A standard coil marked 3W is found to ha...

 A standard coil marked 3W is found to have a true resistance of 3.115 W at 300 K. Calculatge the temperature at which marking is correct. Temperature coefficient of resistance of the material of the coil is `4.2 xx 10^(-300C^(-1)`.

Text Solution

Verified by Experts

The correct Answer is:
`290.2K`
`t = 300 K = 300- 273 = 27^(@)C`
`R_(27) = R_(0)(1+ alpha xx 27)`
`R_(27) = R_(0)(1+ alpha xx 27)`……(i)
`:. 3.115 = R_(0) (1+ 4.3 xx 10^(-3) xx27)` ....(i)
and `3 = R_(0)(1+ 4.2 xx 10^(-3) xx t)`…..(ii)
`:. (3)/(3.115) = (1 + 4.2 xx 10^(-3) xx t)/(1+ 4.2 xx 10^(-3) xx 27)`
On solving we get `t = 17.21^(@)C`
`= 17.21 xx 275 = 290.2K`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • CURRENT ELECTRICITY

    PRADEEP|Exercise Problems for Practice (B)|2 Videos

  • CURRENT ELECTRICITY

    PRADEEP|Exercise Fill in the blanks|4 Videos

  • COMMUNICATION SYSTEMS

    PRADEEP|Exercise MODEL TEST PAPER-2|9 Videos

  • DUAL NATURE OF RADIATION AND MATTER

    PRADEEP|Exercise Exercise|191 Videos

Similar Questions

Explore conceptually related problems

A standard coil marked 3 Omega is found to have a true resistance of 3.115 Omega at 300 K. Calculate the temperature at which marking is correct. Temperature coefficient of resistance of the material of the coil is 4.2xx10^(-3) .^(@)C^(-1) .

A standard coil marked 5 Omega is found to have a resistance of 5.128 Omega at 30^@C . Calculate the temperature at which the marking is correct. The temperature coefficient of resistance of the material of the coil is .0042^@C^(-1) .

Knowledge Check

  • The resistance of a wire at room temperature 30^@C is found to be 10 Om now to increase the resistance by 10% the temperature of the wire must be [the temperature coefficient of resistance of the material of the wire is 0.002 per @C ]

    A
    `36^@C`
    B
    `83^@C`
    C
    `63^@C`
    D
    `33^@C`

  • The resistance of a wire at room temperature 30^@C is found to be 10 Om now to increase the resistance by 10% the temperature of the wire must be [the temperature coefficient of resistance of the material of the wire is 0.002 per @C ]

    A
    `36^@C`
    B
    `83^@C`
    C
    `63^@C`
    D
    `33^@C`

  • A wire has a resistance of 3.1 Omega at 30°C and a resistance 4.5 Omega at 100°C. The temperature coefficient of resistance of the wire

    A
    `0.008^(@) C^(-1)`
    B
    `0.0034^(@) C^(-1)`
    C
    `0.0025^(@) C^(-1)`
    D
    `0.0012^(@) C^(-1)`

    • Similar Questions

    Explore conceptually related problems

    A standard coil marked 2 Omega is found to have a resistance of 2.118 Omega " at " 30^(@)C . Calculate the temperature at which the marking is correct. The temperature coefficient of the resistance of the material of the coil is 0.0042 .^(@)C^(-1) .

    A wire has a resistance of 2.1 Omega at 300 K and a resistance of 2.7 Omega at 373 K. Determine the temperature coefficent of resistance of the material.

    The resistance of a wire at room temperature 30^(@)C is found to be 10 Omega . Now to increase the resistance by 10% , the temperature of the wire must be [ The temperature coefficient of resistance of the material of the wire is 0.002 per .^(@)C ]

    The resistance of a platinum wire is 15 Omega at 20^(@)C . This wire is put in hot furnace and lthe resistance of the wire is found to be 40 Omega . Find the temperature of the hot furnace if temperature coefficient of resistance of platinum is 3.6 xx 10^(-3)^(0)C^(-1)

    If the resistance of a conductor is 5 Omega at 50^(@)C and 7Omega at 100^(@)C then the mean temperature coefficient of resistance of the material is

    Home
    Profile