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

Related Mcqs:

1. 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

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

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

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. Ordinary mercury in glass thermometer is used for measuring temperature upto 120°C. However, for measuring higher temperature upto __________ °C, thermometer is made by filling nitrogen under pressure above the mercury, which stops the evaporation of mercury and reduces the chance of broken thread of mercury?

   A. 250
   B. 350
   C. 550
   D. 700

7. 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

8. Nickel percentage in invar which is an iron-nickel alloy, and is used as a thermocouple material is __________________?

   A. 12
   B. 36
   C. 54
   D. 68

9. 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

10. Which thermocouple can be used to measure a temperature of around 1400°C ?

    A. Copper-constantan
    B. Aluminium-Chromel
    C. Platinum-platinum + rhodium
    D. None of these