Measurement of sub-zero Celsius temperature in industry is done most commonly by __________________?

A. Thermocouples
B. Resistance thermometers
C. Gas thermometers
D. Bi-metallic thermometers

Suppose that the gain, time constant and dead time of a process with the following transfer function: Gc(s) = 10 exp( – 0.1s)/(0.5s + 1) are known with a possible error of ± 20% of their values. The largest permissible gain Kc of a proportional controller needs to be calculated below taking the values of process gain, time constant and dead time as________________?

A. 8, 0.6, 0.08
B. 12, 0.6, 0.12
C. 8, 0.6, 0.12
D. 12, 0.4, 0.08

Working principle of radiation pyrometer is based on the __________________?

A. Wien’s law
B. Kirchoff’s law
C. Stefan Boltzmann law
D. Seebeck effect

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

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

In a shell and tube heat exchanger, the flow rate of heating/cooling fluid is the ______________ variable?

A. Load
B. Controlled
C. Manipulated
D. None of these

In a single tank system, the transfer function of _____________ to inlet flow rate is 1/(TS+1)?

A. Outlet flow rate
B. Level
C. Both A. & B.
D. Neither A. nor B.

In an exothermic chemical reactor, the manipulated variable is the flow rate of_______________?

A. Coolant
B. Reactants
C. Product
D. None of these

A first order system with a time constant of 1 min is subjected to frequency response analysis. At an input frequency of 1 radian/min, the phase shift is______________?

A. 45°
B. -90°
C. -180°
D. -45°

Working principle of disappearing filament type optical pyrometer is based on the ________________?

A. Wien’s law
B. Seebeck effect
C. Kirchoff’s law
D. Peltier effect

Which of the following instruments is not used for measuring sub-zero (<0°) temperatures ?

A. Platinum resistance thermometer
B. Mercury in glass thermometer
C. Vapor pressure thermometer
D. Radiation pyrometer