Relationship between absorption/evolution of heat at the thermocouple junctions and the current flow in the circuit is given by _____________ effect?

Related Mcqs:

1. Which of the following relates the absorption & evolution of heat at the junctions of a thermocouple to the current flow in the circuit ?

   A. Seebeck effect
   B. Peltier effect
   C. Joule heating effect
   D. Thomson effect

2. 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

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 temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured by a/an _____________ thermocouple?

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

7. Water is entering a storage tank at a temperature T0 and flow rate Q0 and leaving at a flow rate Q and temperature T. There are negligible heat losses in the tank. The area of cross-section of the tank is A0. The model that describes the dynamic variation of temperature of water in the tank with time is given as________________?

   A. Q0(T0 – T) = Ac . h (dT/dt)
   B. Q0T0 – QT = Ac . h (dT/dt)
   C. Q(T0 – T) = Ac . h (dT/dt)
   D. Q(T0 – T) = Ac . (dTH/dt)

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

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

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

    A. 0.1
    B. 3
    C. 13
    D. 29