What is the normal percentage of rhodium in platinum + rhodium element used in the thermocouple ?

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. 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

3. 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

4. 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.

5. Platinum resistance thermometer can be used upto antimony point which is ____________ °C, and is the temperature of equilibrium between solid antimony & liquid antimony at normal atmospheric pressure?

   A. 961.93
   B. 630.74
   C. 1064.43
   D. 1261.93

6. The frequency response of a dynamic element shows a constant magnitude ratio at all frequencies. The element exhibits a negative phase shift at all frequencies. The absolute value of the phase shift increases linearly with frequency. The element has the transfer function ?

   A. e-ηS
   B. (T1S + 1)/(T2S + 1)
   C. (T1S/(T2S + 1)
   D. (T1S + 1)/(T2S

7. 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

8. Platinum resistance thermometer is the international standard for temperature measurement between __________________?

   A. Triple point of hydrogen and freezing point of antimony
   B. 13.81°K to 903.9°K
   C. Both A. and B.
   D. Neither A. nor B.

9. With increase in temperature, the electrical conductivity of the platinum used in the resistance thermometer ?

   A. Increases
   B. Decreases
   C. Remain constant
   D. Increases exponentially

10. Which of the following thermocouple materials does not contain nickel ?

    A. Alumel
    B. Chromel
    C. Constantan
    D. None of these