Which of the following relates the emf. generated in a single homogeneous wire to the temperature difference ?

Related Mcqs:

1. Emf generated in a thermocouple depends on the temperature ___________________?

   A. Of cold junction only
   B. Of hot junction only
   C. Difference between hot and cold junctions
   D. Difference between cold junction and atmospheric temperature

2. Strain gage uses an electrical conductor wire, which when elastically stretched increases in length and reduces in diameter. Both these dimensional changes result in ____________ in the electrical resistance of the wire ?

   A. No change
   B. Decrease
   C. Increase
   D. Exponential decrease

3. Emf developed by a thermocouple while measuring a temperature of 800°C is about 31 mV. The type of thermocouple used is________________?

   A. Chromel-alumel
   B. Iron-constantan
   C. Platinum-platinum + rhodium
   D. None of these

4. Emf developed by a thermocouple while measuring a temperature of 400°C is 22 mV. The type of thermocouple used is ___________________?

   A. Chromel-alumel
   B. Iron-constantan
   C. Platinum-rhodium
   D. Platinum-platinum + rhodium

5. Emf developed by a thermocouple, while measuring a temperature of 600°C is about 5.5 mV. The type of thermocouple used is_______________?

   A. Chromel-alumel
   B. Iron-constantan
   C. Platinum-platinum + rhodium
   D. Either A., B. or C.

6. The thermal emf-temperature relationship of most thermocouples is_________________?

   A. Linear
   B. Parabolic
   C. Exponential
   D. Square root

7. Out of the following thermocouple wire insulating material, the highest temperature rating is for________________?

   A. Teflon
   B. Ceramic fibre
   C. Asbestos
   D. Fibre glass

8. Which of the following measurements can be made by the measurement of emf ?

   A. pH value
   B. Degree of hydrolysis
   C. Composition of complex ions
   D. All A., B. & C.

9. The maximum service temperature for fibre glass used as thermocouple wire insulation material is __________ °C?

   A. 250
   B. 500
   C. 750

   D. 1000

10. The calibration data of a thermocouple with its cold junction at 0°C are given below. The hot junction of the thermocouple is placed in a bath at 80°C, while its cold junction is at 20°C. What is the emf of thermocouple ?

    A. 3.26 mv
    B. 0.80 mv
    C. 2.46 mv
    D. 2.43 mv