# Practice Test: Question Set - 01

**1. When a bare thermocouple is covered by a protective sheath, the response becomes**

- (A) Faster
and oscillatory

- (B) Faster
and non-oscillatory

- (C) Slower
and oscillatory

- (D) Slower
and non-oscillatory

**2. Which of the following thermocouples is incapable of measuring sub-zero (i.e., < 0°C) temperature?**

- (A) Chromel-alumel

- (B) Iron-constantan

- (C) Platinum-platinum
+ rhodium

- (D) Copper-constantan

**3. __________ temperature scale assigns 0° to the 'ice point' and 80° to the 'steam point'.**

- (A) Celsius

- (B) Rankine

- (C) Reaumur

- (D) Fahrenheit

**4. "An emf of the order of mV is generated when two solutions of different hydrogen ion concentration are separated by a thin glass wall". This is the working principle of a**

- (A) pH
meter

- (B) Polarimeter

- (C) Chromatograph

- (D) Polarograph

**5. The transfer function of a process is 1/(16**

*s*^{2}+ 8*s*+ 4). If a step change is introduced into the system, then the response will be- (A) Under
damped

- (B) Critically
damped

- (C) Over
damped

- (D) None
of these

**6. A control system has the following transfer function**

The initial value of the corresponding time function is

*F*(*s*) = [(*s*- 1)(*s*+ 1)]/[*s*(*s*- 2)(*s*+ 4)]The initial value of the corresponding time function is

- (A) 1

- (B) 1/8

- (C) 7/8

- (D) -1

**7. Bode diagram is a plot of**

- (A) log (

*AR*)

*vs*. log (

*f*) and (Ï†) vs. log (

*f*)

- (B) log (

*AR*)

*vs*.

*f*and log Ï†

*vs*.

*f*

- (C)

*AR*

*vs*. log (

*f*) and Ï†

*vs*. log (

*f*)

- (D) None
of these

**8. Block diagram of a simple standard control system is shown below in the figure. Which of the following statement about the above control system is wrong?**

- (A) The
transfer functions of the measuring element and the process is represent
by

*H*and

*G*

_{2}respectively

- (B) The overall
transfer function for the change in load (

*X*= 0) is given by

*Y*/

*X*

_{1}= (

*G*

_{c}.

*G*

_{1}.

*G*

_{2})/(1 +

*G*

_{c}.

*G*

_{1}.

*G*

_{2}.

*H*)

- (C) The overall
transfer function for the change in set point (

*X*

_{1}= 0) is given by

*Y*/

*X*= (

*G*

_{c}.

*G*

_{1}.

*G*

_{2})/(1 +

*G*

_{c}.

*G*

_{1}.

*G*

_{2}.

*H*)

- (D) Manipulated
variable is represented by C

**9. A bolometer is**

- (A) Used
for the measurement of thermal radiation

- (B) An
element which senses optical input and delivers thermal output

- (C) Both (a)
& (b)

- (D) Neither (a)
nor (b)

**10. The frequency at which maximum amplitude ratio is attained is called the __________ frequency.**

- (A) Corner

- (B) Resonant

- (C) Cross-over

- (D) Natural

**11. The time constant of a first order process with resistance R and capacitance C is**

- (A)

*R*+

*C*

- (B)

*R*-

*C*

- (C)

*RC*

- (D) 1/

*RC*

**12. Thermocouple is suitable for measuring**

- (A) Liquid
temperatures only

- (B) Very high
temperatures only

- (C) Very
low temperatures only

- (D) Both
high and low temperatures

**13. Very low pressure is expressed in microns (Î¼), which is equal to __________ mm of Hg column (absolute) at 0°C.**

- (A) 0.0001

- (B) 0.001

- (C) 0.01

- (D) 0.1

**14. For the time domain function**

*f*(*t*) =*t*, the Laplace transform of ∫_{0}^{t}*f*(*t*)*dt*is given by- (A) 1/2

*S*

^{3}

- (B) 2/

*S*

^{3}

- (C) 1/

*S*

^{3}

- (D) 2/

*S*

^{2}

**15. What is the overall transfer function (**

*C*/*R*) of the following block diagram if*G*=*G*_{1}.*G*_{2}.*G*_{3}and*H*=*H*_{1}.*H*_{2}.- (A) 1/(1 +

*GH*)

- (B)

*G*/(1 +

*GH*)

- (C)

*H*/(1 +

*GH*)

- (D)

*G*/(1 -

*GH*)

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