Photoelectric pyrometers are suitable in the temperature range of ________________ °C?

Related Mcqs:

1. Radiation pyrometers as compared to thermocouples____________________?

   A. Has a slower speed of response
   B. Can measure higher temperature
   C. Can’t measure the temperature of moving objects
   D. Is more affected by corrosive atmosphere

2. A photo electric device in which the resistance of the metal is directly proportional to the light striking on it, is known as photo-conductive cell. Photoelectric transducers are used for the measurement of those parameters, which can be used to produce variation in_______________?

   A. Light intensity
   B. Current
   C. Flux density
   D. Voltage

3. Pick out the most suitable instrument for measuring temperature in the range of-40 to 425°C ?

   A. Mercury thermometer
   B. Bimetallic thermometer
   C. Radiation pyrometer
   D. None of these

4. Which of the following is not suitable for measuring the temperature of a red hot object in the range of 800 – 1600°C ?

   A. Optical pyrometer
   B. Radiation pyrometer
   C. Photoelectric pyrometer
   D. Thermocouples

5. Normal mercury thermometer can be used to measure a temperature of about 300°C. However, its maximum temperature measurement range can be increased upto about 500°C by__________________?

   A. Filling nitrogen under pressure in the stem
   B. Increasing the diameter of the tube
   C. Using steel tube in place of glass tube
   D. Accounting for the tube expansion

6. 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)

7. Nitrogen gas constant volume thermometer is suitable for measuring a temperature of _____________ °C?

   A. 0-100
   B. < 0
   C. > 100
   D. > 50

8. Helium gas constant volume thermometer is suitable for the measurement of a temperature of ______________ °C?

   A. < 100
   B. < 0
   C. > 0
   D. > 800

9. Which of the following thermocouples is the most suitable for measuring a temperature of about 1600°C in an oxidizing atmosphere ?

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

10. For measuring the temperature of a red hot furnace, which is the most suitable instrument ?

    A. Platinum resistance thermometer
    B. Thermocouple
    C. Optical pyrometer
    D. Bimetallic thermometer