Top 60 Unit Operations & Power Plant Instrumentation Objective Questions and Answers 1. What is the removal of fine particle sand from dissolved solids called? a) Filteration b) sedimentation c) disinfection d) deoxidation Answer: Filteration 2. In distillation, overhead product contains  a) Only one component b) two components c) any number of component d) saturated liquid Answer: any number of component 3. Separation of two or more components of a liquid solution can not be achieved by a) Fractional Crystallisation b) Liquid Extraction c) Absorption d) Evaporation Answer: Absorption 4. Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases. a) Chemical properties b) Physical properties c) Degree of turbulence d) Interfacial area Answer: Chemical properties 5. The main function of centrifugal pumps are to ________  a) Transfer speed b) Transfer pressure c) Transfer temperature d) Transfer energy Answer: Transfer energy 6. Dryi

  Top 50 Process Loop Components (PLC) Objective Questions and Answers 1. A basic process control loop will consist of ________ a) Signal converter, resistor, knob, and control valve b) Transducer, valve packing, hex-head wrench, and tubing c) Transmitter, controller, I/P converter, and control valve d) Resistor, capacitor, terminal block, and battery Answer: Transmitter, controller, I/P converter, and control valve 2. In a home heating system, room temperature is ________ A) Setpoint B) Manipulated variable C) Process variable D) Load Variable Answer: Process variable 3. Which is/are the component/s are needed for a 4 mA to 20 mA signal?  A) A power supply B) Wire C) A transmitter D) All of the above Answer: All of the above* 4. Identify the proper sequence of valve actions for a three-valve manifold and bleed when taking a differential pressure transmitter out of service:  A) Close one block valve, open equalizing valve, close other block valve, open bleed B) Open bleed, close one bl

  PID Controller 1. In a proportional temperature controller, if the quantity under the heater increases the offset will: a) Increase b) Reduce c) Remain uneffected d) None of the above Answer: Increase 2. The term reset control refers to: a) Proportional b) Integral c) Derivative d) None of the above Answer: Integral 3. In a PID controller, the overshoots has increased. The derivative time constant has to be __ so as to reduce the overshoots: a) Increased b) Reduced c) Reduced to zero d) None of the above Answer: Increased 4. Proportional band of the controller is expressed as: a) Gain b) Ratio c) Percentage d) Range of control variables Answer: Percentage 5. When derivative action is included in a proportional controller, the proportional band: a) Increases b) Reduces c) Remains unchanged d) None of the above Answer: Remains unchanged 6. Proportional band of a controller is defined as the range of: a) Measured variable to the set variable b) Air output as the measured variable varies

  Reliability 1. In parallel configuration of five components, the entire system will fail if _____ a) any two components fail b) any three components fail c) all the components fail d) any one components fail Answer: all the components fail 2. System reliability for components kept in series _______ as the number of components increases. a) Increases b) Decreases c) Remains unchanged d) Cannot be determined Answer: Decreases 3. Reliability is the probability of a system or service to perform its intended function satisfactorily over a specific period of time under specific conditions. a) True b) False Answer: True 4. Reliability is a measure of how quality changes over time. a) True b) False Answer: True 5. What does the graph of ‘bathtub curve’ represent? a) Failure rate v/s Mean b) Failure rate v/s Time c) Failure rate v/s Distance d) Failure rate v/s Velocity Answer: Failure rate v/s Time 6. The life-test sample plans that are terminated when a pre-assigned number of failures occur

  V to I Converters (Voltage to Current Converter) 1. Find the voltage drop across the zener diode in the zener diode tester from the given specifications: I Zk =1mA, V Z  =6.2v, input voltage= 1.2v, output voltage =3.2v and resistance in series with meter =150Ω. a) 6.2mA b) 8mA c) 21.33mA d) Cannot be determine Answer: 6.2mA 2. For voltage to current converter with grounded load, establish a relation between the non-inverting input terminals and load current a) V 1  = [V in +V o -(I L ×R)] /2 b) V 1  = [V in -V o -(I L ×R)] /2 c) V 1  = [V in +V o -I L +R] /2 d) V 1  = [V in +V o +(I L ×R)] /2 Answer: V 1  = [V in +V o -(I L ×R)] /2 3. Voltage to current converter is also called as a) Current series positive feedback amplifier b) Voltage series negative feedback amplifier c) Current series negative feedback amplifier d) Voltage series positive feedback amplifier Answer: Current series negative feedback amplifier 4. The maximum current through the load in all applicatio

  Converter Multiple Choice Questions and Answers 1. A rotary converter in general construction and design is more or less like a) Transformer b) An induction motor c) An alternator d) Any DC machine Answer: Any DC machine 2. In which of the following equipment direct current is needed? a) Telephones b) Relays c) Time switches d) All of the above Answer: All of the above 3. In a single phase rotary converter the number of slip rings will be a) Two b) Three c) Four d) Five Answer: Two 4. A rotary converter is a single machine with a) One armature and one field b) Two armatures and one field c) One armatures and two fields d) None of the above Answer: One armature and one field 5. With a motor converter it is possible to obtain DC voltage only up to a) 200 to 400 v b) 600 to 800 v c) 1000 to 1200 v d) 1700 to 2000 v Answer: 1700 to 2000 v 6. A rotary converter combines the function of a) An induction motor and a DC generator b) A synchronous motor and a DC generator c) A dc series motor

  Instrumentation Amplifier 1. The length of the transmission lines are a) Longer than 10 meters b) Shorter than 10 meters c) Equals to 10 meters d) None of the mentioned Answer: None of the mentioned 2. Transmission line are used for a) Output signal b) Input signal c) Signal transfer d) All of the mentioned Answer: Signal transfer 3. An instrumentation system does not include a) Transducer b) Instrumentation amplifier c) Automatic process controller d) Tester Answer: Tester 4. Strain gage is an example of which device? a) Transducer b) Voltage follower c) Integrator d) Differentiator Answer: Transducer 5. Why output of transducer is not directly connected to indicator or display? a) Low level output is produced b) High level output is produced c) No output is produced d) Input is fed directly Answer: Low level output is produced 6. General purpose op-amps are used in applications as a) Instrumentation amplifier b) Differential instrumentation amplifier c)

  Linear Opto Isolator  1. A device which is made of isolators and follows a closed loop path is called as a ____ a) Circulator b) Gyrator c) Attenuator d) Connector Answer: Circulator 2. It is a passive device which allows the flow of optical signal power in only one direction and preventing reflections in the backward direction. a) Fiber slice b) Optical fiber connector c) Optical isolator d) Optical coupler Answer: Optical isolator 3. Magneto-optic devices can be used to function as isolators. a) True b) False Answer: True 4. A combination of a FBG and optical isolators can be used to produce non-blocking optical wavelength division add/draw multiplexers. a) True b) False Answer: False 5. How many implementation methods are available for optical isolators? a) One b) Four c) Two d) Three Answer: Three 6. An FBG is developed within a fiber core having a refractive index of 1.30. Find the grating period for it to reflect an optical signal with a wavelength of 1.33

  Phase Locked Loop   1. At what range the PLL can maintain the lock in the circuit? a) Lock in range b) Input range c) Feedback loop range d) None of the mentioned Answer: Lock in range 2. At which state the phase-locked loop tracks any change in input frequency? a) Free running state b) Capture state c) Phase locked state d) All of the mentioned Answer: Phase locked state 3. The output voltage of phase detector is a) Phase voltage b) Free running voltage c) Error voltage d) None of the mentioned Answer: Error voltage 4. Free running multivibrator is also called as a) Stable multivibrator b) Voltage control oscillator c) Square wave oscillator d) Pulse stretcher Answer: Voltage control oscillator 5. What is the function of low pass filter in phase-locked loop? a) Improves low frequency noise b) Removes high frequency noise c) Tracks the voltage changes d) Changes the input frequency Answer: Removes high frequency noise 6. What is the need to generate corrective control voltage? a) To

  Top 50 Instrument and System Design (ISD) Objective Questions and Answers 1. What is the operating temperature range of consumer electronics products? a) 0°C to 70°C b) -25°C to 85°C c) -55°C to 125°C  d) -75°C to 90°C Answer: 0°C to 70°C 2. Which terminology enables the user to develop certain novel features and modify the designs as per the requirement level? a) Simulation b) Prototype c) Product d) Quality Answer: Prototype 3. First digit of IP standard shows the degree of protection against a) Solid object and dust b) Liquids c) Mechanical protection d) Non of these Answer: Solid object and dust 4. The manufacturing of the product starts after a) Pilot production batch b) Environmental testing c) QA testing d) Paper Design Answer: QA testing 5. Which among the below mentioned approaches belongs to the category of In-circuit Testing? a) Impedance Testing b) Component Testing c) Apply Signal and check output d) All of the these Answer: All of the these 6. The effects of EMI can be

  Signal Conditioners 1. What is the full form of IIR in terms of signal filtering? a) Infinite impulse response b) Infinite impulse reduction c) Infinite impulse recombination d) Instant impulse response Answer: Infinite impulse response 2. What is the full form of FIR in terms of signal filtering? a) Finite impulse response b) Finite impulse reduction c) Finite impulse recombination d) Filthy impulse response Answer: Finite impulse response 3. Which filter contains entirely passive elements? a) Electrical filter b) Mechanical filter c) Digital filter d) Optical filter Answer: Electrical filter 4. A system is said to be non causal if its present output depends on the future inputs. a) True b) False Answer: True 5. A system is said to be causal if its output depends on the future inputs. a) True b) False Answer: False 6. Derivative of a unit step signal is zero everywhere. a) True b) False Answer: False 7. Capacitor can be used for signal filtering. a) True b) False Answer: True 8. Whi

  Fluid Power Actuators 1. What is the advantage of using a single acting cylinder? a) high cost and reliable b) honing inside the inner surface of pump is not required c) piston seals are not required d) all the above Answer: piston seals are not required 2. What is the function of electric actuator? a) converts electrical energy into mechanical torque b) converts mechanical torque into electrical energy c) converts mechanical energy into mechanical torque d) none of the above Answer: converts electrical energy into mechanical torque 3. Match the following group 1 items with group 2 items and select the correct option. 1. Radial motor _____________ A. Swash plate 2. Axial motor ______________ B. Crank shaft motor 3. Orbit ____________________ C. Vane motor 4. Low torque motor ________ D. Geroller motor a) 1-B, 2-A, 3-D, 4-C b)  1-A, 2-C, 3-B, 4-D c)  1-C, 2- A, 3-B, 4-D d) 1-B, 2-D, 3-A, 4-C Answer: 1-B, 2-A, 3-D, 4-C 4. Which of the following is a hydraulic cylinder based on construc