Process Control and Instrumentation MCQs

Question 1

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.

Accepted Answer

630.74

Answer

961.93

Answer

1064.43

Answer

1261.93

Question 2

Pick out the first order system from among the following.

Accepted Answer

Mercury in glass thermometer kept in boiling water

Answer

Damped vibrator

Answer

Interacting system of two tanks in series

Answer

Non-interacting system of two tanks in series

Question 3

The transfer function of a first order system is

Accepted Answer

$$\frac{1}{{{	ext{Ts}} + 1}}$$

Answer

$$\frac{1}{{{	ext{Ts}}}}$$

Answer

$$\frac{{	ext{s}}}{{{	ext{Ts}} + 1}}$$

Answer

None of these

Question 4

When the damping co-efficient (ξ) is unity, the system is

Accepted Answer

Critically damped

Answer

Overdamped

Answer

Underdamped

Answer

Highly fluctuating

Question 5

Specific gravity of a liquid can not be measured by a/an

Accepted Answer

Anemometer

Answer

Specific gravity bottle

Answer

Pycnometer

Answer

Hydrometer

Question 6

Continuous measurement of moisture in paper is done by

Accepted Answer

High resistance Wheatstone's bridge circuit

Answer

Sling psychrometer

Answer

Hair-hygrometer

Answer

Weighing

Question 7

Specific conductance is defined as the reciprocal of resistance in ohms of 1 c.c. of liquid at a specified temperature. Its value for distilled water is about __________ micro mho/cm 3 .

Accepted Answer

1

Answer

50

Answer

100

Answer

10

Question 8

Thermocouple in a thermal well behaves as a true

Accepted Answer

Multiple first order system

Answer

First order system

Answer

Second order system (overdamped)

Answer

Second order system (underdamped)

Question 9

A sinusoidal variation in the input passing through a linear first order system

Accepted Answer

Gets attenuated (magnitude decreases)

Answer

Becomes more oscillatory (frequency increases)

Answer

Becomes less oscillatory (frequency decreases)

Answer

Gets amplified (magnitude increases)