# Interview Q & A **URL:** https://forumautomation.com/c/interview-questions-and-answers/32.md [Latest](https://forumautomation.com/latest.md) · [Categories](https://forumautomation.com/categories.md) · [Tags](https://forumautomation.com/tags.md) --- ## [Saudi Aramco Interview questions: Instrument/DCS Engineer](https://forumautomation.com/t/saudi-aramco-interview-questions-instrument-dcs-engineer/193)
**Author:** [@instrumen](https://forumautomation.com/u/instrumen)\ **Replies:** 29\ **Last updated:** [August 7, 2019, 7:35pm UTC](https://forumautomation.com/t/saudi-aramco-interview-questions-instrument-dcs-engineer/193 "2019-08-07T19:35:00Z")
what is cascade loop and how it work and why it used instead of PID single loop? In cascade, Which loop is faster and slower? Please explain with loop drawing and example… --- ## [Interview Question for Automation,DCS,PLC Engineers](https://forumautomation.com/t/interview-question-for-automation-dcs-plc-engineers/215)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 11\ **Last updated:** [October 21, 2017, 11:54am UTC](https://forumautomation.com/t/interview-question-for-automation-dcs-plc-engineers/215 "2017-10-21T11:54:04Z")
Draw system architecture showing PLC, SCADA/MMI, networking devices communication protocol details like IP address etc. Draw detailed block diagram of any field parameter like temp, pressure reading coming to PLC can be… --- ## [Why 4-20 ma signal is used in Industrial instrumentation?](https://forumautomation.com/t/why-4-20-ma-signal-is-used-in-industrial-instrumentation/2248)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 4\ **Last updated:** [September 4, 2024, 4:45pm UTC](https://forumautomation.com/t/why-4-20-ma-signal-is-used-in-industrial-instrumentation/2248 "2024-09-04T16:45:54Z")
4-20 ma Signal in Industrial Instrumentation Signal Flow from Instrument to Controller (PLC/DCS/Stand alone controller) - A physical signal(Temperature / Pressure / Level / Flow etc) measured by a sensor is converted t… --- ## [Basic Instrumentation - Interview Questions and Answers](https://forumautomation.com/t/basic-instrumentation-interview-questions-and-answers/1849)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [March 19, 2017, 5:32pm UTC](https://forumautomation.com/t/basic-instrumentation-interview-questions-and-answers/1849 "2017-03-19T17:32:46Z")
Interview Questions and Answers - Basic Instrumentation What is closed loop ? A Closed control loop exists where a process variable is measured,compared to a setpoint and action is taken to correct any deviation from s… --- ## [Basic Electrical interview questions & answers](https://forumautomation.com/t/basic-electrical-interview-questions-answers/3360)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [March 31, 2018, 4:58pm UTC](https://forumautomation.com/t/basic-electrical-interview-questions-answers/3360 "2018-03-31T16:58:38Z")
1. Why we use 3-phase supply? Why are not 4 or something else? Answer: 3 phase power generating and delivering is more efficient than 2 phase which in turn is more efficient than 1 phase. Similarly, going up in the nu… --- ## [30 Mostly asked PLC Interview Questions](https://forumautomation.com/t/30-mostly-asked-plc-interview-questions/4231)
**Author:** [@areejsidhik](https://forumautomation.com/u/areejsidhik)\ **Replies:** 0\ **Last updated:** [July 26, 2018, 7:08am UTC](https://forumautomation.com/t/30-mostly-asked-plc-interview-questions/4231 "2018-07-26T07:08:54Z")
1. What is Programmable Logic Controllers (PLCs)? Ans. Programmable Logic Controllers (PLCs): Programmable Logic Controllers (PLCs) are the micro processor controller devices situated at the remote sites of the plant o… --- ## [What are the important symbols used in P&ID diagram](https://forumautomation.com/t/what-are-the-important-symbols-used-in-p-id-diagram/2479)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [October 19, 2017, 9:45pm UTC](https://forumautomation.com/t/what-are-the-important-symbols-used-in-p-id-diagram/2479 "2017-10-19T21:45:36Z")
All the devices like transmitters, gauges, and other equipment etc., in a control loop, cannot be picturised to understand the logic. So in a P& id diagram, all the devices are symbolised. Letters and numbers are writt… --- ## [PLC (Programmable logic controller) Interview questions](https://forumautomation.com/t/plc-programmable-logic-controller-interview-questions/521)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [October 18, 2015, 6:15am UTC](https://forumautomation.com/t/plc-programmable-logic-controller-interview-questions/521 "2015-10-18T06:15:43Z")
1.What is PLC? PLC are solid state members of the computer family using integrated circuit instead of electromechanical devices to implement control functions. 2.What are the two basic sections of PLC? CPU The Input/Ou… --- ## [Instrumentation Interview question : What is the difference between Transducer and Transmitter?](https://forumautomation.com/t/instrumentation-interview-question-what-is-the-difference-between-transducer-and-transmitter/248)
**Author:** [@automate](https://forumautomation.com/u/automate)\ **Replies:** 1\ **Last updated:** [March 9, 2015, 7:22pm UTC](https://forumautomation.com/t/instrumentation-interview-question-what-is-the-difference-between-transducer-and-transmitter/248 "2015-03-09T19:22:39Z")
Transducer - Transducer converts one form of energy into another form. For example : Converts mechanical energy into electrical energy. Thermocouple. Converts temperature into electrical form. Transmitter : Transmitter … --- ## [How to calculate measurement value from 4-20 ma transmitter output?](https://forumautomation.com/t/how-to-calculate-measurement-value-from-4-20-ma-transmitter-output/2254)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [August 28, 2017, 3:18am UTC](https://forumautomation.com/t/how-to-calculate-measurement-value-from-4-20-ma-transmitter-output/2254 "2017-08-28T03:18:11Z")
The equation to calculate Measurement Value is MV = { \[(TV - TRL) / (TRU - TRL) \] \*(MRU-MRL)} + MRL MV = Measurement Value TRL = Transmitter range low value Eg:4 ma TRU = Transmitter range upper value Eg: 20 ma. … --- ## [What are the major terminologies related to Instrument calibration?](https://forumautomation.com/t/what-are-the-major-terminologies-related-to-instrument-calibration/1623)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [January 4, 2017, 4:50am UTC](https://forumautomation.com/t/what-are-the-major-terminologies-related-to-instrument-calibration/1623 "2017-01-04T04:50:39Z")
Accuracy - The degree of an indicated value to an accepted standard value or true value. Calibration - correcting or determining the error of an existing scale or of evaluating one quantity in terms of reading from ano… --- ## [SCADA system interview questions](https://forumautomation.com/t/scada-system-interview-questions/4328)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [August 7, 2018, 12:47pm UTC](https://forumautomation.com/t/scada-system-interview-questions/4328 "2018-08-07T12:47:13Z")
1. What is SCADA? SCADA stands for Supervisory Control and Data Acquisition. It is an industrial control system that controls and monitor. The operator can control and monitor the process from the SCADA station. 2. What… --- ## [Interview questions - Basic instrumentation](https://forumautomation.com/t/interview-questions-basic-instrumentation/2186)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 1\ **Last updated:** [August 18, 2017, 4:50am UTC](https://forumautomation.com/t/interview-questions-basic-instrumentation/2186 "2017-08-18T04:50:55Z")
Define physical quantity ? Any quantity which can be measured is known as physical quantity. Define Measurend ? A physical quantity which is being measured. Define sensors? Sensors are devices which transform one ph… --- ## [What is the difference between short circuit Protection and Overload protection?](https://forumautomation.com/t/what-is-the-difference-between-short-circuit-protection-and-overload-protection/2252)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [August 27, 2017, 11:53pm UTC](https://forumautomation.com/t/what-is-the-difference-between-short-circuit-protection-and-overload-protection/2252 "2017-08-27T23:53:17Z")
Both Short circuit and overload protection devices protect motor circuit from over current. Over current or excess current is a situation where a larger than intended electric current exists,which leads to excessive gen… --- ## [Level measurement interview questions](https://forumautomation.com/t/level-measurement-interview-questions/3029)
**Author:** [@areejsidhik](https://forumautomation.com/u/areejsidhik)\ **Replies:** 0\ **Last updated:** [January 25, 2018, 12:35pm UTC](https://forumautomation.com/t/level-measurement-interview-questions/3029 "2018-01-25T12:35:50Z")
What is level? The total quantity of substance stored in a tank or vessel. Different types of level measurement instruments used in industries are Gauge glass, pressure gauge -scale graduated in %of level, rope an… --- ## [Instrument and process equipment symbols](https://forumautomation.com/t/instrument-and-process-equipment-symbols/2357)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [September 28, 2017, 3:13pm UTC](https://forumautomation.com/t/instrument-and-process-equipment-symbols/2357 "2017-09-28T15:13:15Z")
The instrument symbols are as per ISA 5.1 standards, which are applicable in Process Flow Diagrams (PFDs), Process and Instruments, Diagrams (P&IDs), and loop diagrams Line types: Bubble type: Process valve type: … --- ## [Common Interview Questions: Instrument and Control Engineers](https://forumautomation.com/t/common-interview-questions-instrument-and-control-engineers/139)
**Author:** [@instrumen](https://forumautomation.com/u/instrumen)\ **Replies:** 1\ **Last updated:** [April 15, 2018, 1:47pm UTC](https://forumautomation.com/t/common-interview-questions-instrument-and-control-engineers/139 "2018-04-15T13:47:51Z")
What are the process Variables? Define all the process Variable and state their unit of measurement. ? What are the primary elements used for flow measurement? What are the different types of orifice plates and state th… --- ## [PLC (Programmable Logic Control) Interview questions](https://forumautomation.com/t/plc-programmable-logic-control-interview-questions/3319)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 1\ **Last updated:** [April 13, 2018, 3:20am UTC](https://forumautomation.com/t/plc-programmable-logic-control-interview-questions/3319 "2018-04-13T03:20:42Z")
1. What is PLC? It is a class of industrially hardened devices that provides the hardware interface for input sensors and output control element. The field I/p include element like limit switches, sensors, push button an… --- ## [Interview questions and answers - Instrumentation /Automation /Process control engineers](https://forumautomation.com/t/interview-questions-and-answers-instrumentation-automation-process-control-engineers/609)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 2\ **Last updated:** [November 27, 2015, 9:59pm UTC](https://forumautomation.com/t/interview-questions-and-answers-instrumentation-automation-process-control-engineers/609 "2015-11-27T21:59:58Z")
What does PID mean? (Be specific, don’t just define the Three Letter Acronym) Acronym: P=Proportion or gain applied to error to assist in overcoming the deviation. I= Proportion or gain over time applied to error to a… --- ## [What is Loop checking? importance of Loop checking](https://forumautomation.com/t/what-is-loop-checking-importance-of-loop-checking/2346)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [September 26, 2017, 7:33am UTC](https://forumautomation.com/t/what-is-loop-checking-importance-of-loop-checking/2346 "2017-09-26T07:33:17Z")
What is a Loop check? Loop check is an operational check of a control loop. Intended to find out the deficiencies in control loop/ field interface/ HMI Loop checking is the is final stage of a project commissioning. We … --- ## [What is Multivariable control system?](https://forumautomation.com/t/what-is-multivariable-control-system/2498)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [October 22, 2017, 10:18pm UTC](https://forumautomation.com/t/what-is-multivariable-control-system/2498 "2017-10-22T22:18:22Z")
Multivariable Control System Multivariable control system define a system in which the variable the variable interacts strongly. This kind of system must have more than one input and more than one output. A disturbance … --- ## [What are the types of Control Systems?](https://forumautomation.com/t/what-are-the-types-of-control-systems/4823)
**Author:** [@rajeena](https://forumautomation.com/u/rajeena)\ **Replies:** 0\ **Last updated:** [October 2, 2018, 3:30pm UTC](https://forumautomation.com/t/what-are-the-types-of-control-systems/4823 "2018-10-02T15:30:44Z")
What are the types of Control Systems? A control system can be functioned electrically, mechanically, pressure by fluid (gas or liquid), or it can be combination of these ways. Control systems are used to arrange and man… --- ## [50+ Instrumentation Interview questions](https://forumautomation.com/t/50-instrumentation-interview-questions/7666)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 1\ **Last updated:** [September 16, 2020, 9:23am UTC](https://forumautomation.com/t/50-instrumentation-interview-questions/7666 "2020-09-16T09:23:09Z")
1. What is the instrumentation Engineering? Instrumentation engineering is the engineering specialization deals with principle and operation of measuring devices used in electrical, pneumatic, etc. design and configur… --- ## [What are the advantages and disadvantages of Cascade control?](https://forumautomation.com/t/what-are-the-advantages-and-disadvantages-of-cascade-control/1376)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [September 19, 2016, 4:00am UTC](https://forumautomation.com/t/what-are-the-advantages-and-disadvantages-of-cascade-control/1376 "2016-09-19T04:00:33Z")
Advantages of Cascade control Loop- -Isolating the slow outer loop from valve problems and some disturbances. Fast inner loop take care of these. Disadvantages of cascade control loop. -Additional measurement require… --- ## [Basic instrumentation engineering interview questions](https://forumautomation.com/t/basic-instrumentation-engineering-interview-questions/5615)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [December 31, 2018, 4:52pm UTC](https://forumautomation.com/t/basic-instrumentation-engineering-interview-questions/5615 "2018-12-31T16:52:05Z")
What are the process Variable? Flow Pressure Temperature Level Quality i. e. % O2, CO2, pH etc. Define all the process Variable and state their unit of measurement. ? Flow: Defined as volume per unit of time at … --- ## [What is control loop ? What are the two types of control loop?](https://forumautomation.com/t/what-is-control-loop-what-are-the-two-types-of-control-loop/2413)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [October 9, 2017, 12:43am UTC](https://forumautomation.com/t/what-is-control-loop-what-are-the-two-types-of-control-loop/2413 "2017-10-09T00:43:19Z")
What is a control loop? Control loop is a group of components working together as a system to achieve and maintain the desired value of a system variable by manipulating the value of another variable in the control loop… --- ## [Basic instrumentation Interview questions?](https://forumautomation.com/t/basic-instrumentation-interview-questions/3028)
**Author:** [@areejsidhik](https://forumautomation.com/u/areejsidhik)\ **Replies:** 0\ **Last updated:** [January 25, 2018, 8:35am UTC](https://forumautomation.com/t/basic-instrumentation-interview-questions/3028 "2018-01-25T08:35:04Z")
1.What is instrumentation ? Instrumentation is a study of instruments used for indicating ,measuring,recording ,controlling the process variable is called instrumentation .The process variables commonly used in indus… --- ## [DCS Engineer Interview Questions - Fundamentals (Refinery ,Power Plant, Chemical Plant ,Paper)](https://forumautomation.com/t/dcs-engineer-interview-questions-fundamentals-refinery-power-plant-chemical-plant-paper/226)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [January 5, 2015, 2:38am UTC](https://forumautomation.com/t/dcs-engineer-interview-questions-fundamentals-refinery-power-plant-chemical-plant-paper/226 "2015-01-05T02:38:30Z")
Some of the Interview questions for Control System Engineers - DCS (Distributed Control System ) Q) Definition of DCS? A microprocessor based control and Data acquisition system consisting of number of modules operating… --- ## [What are the different problems in control valve?](https://forumautomation.com/t/what-are-the-different-problems-in-control-valve/2948)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [January 10, 2018, 8:16pm UTC](https://forumautomation.com/t/what-are-the-different-problems-in-control-valve/2948 "2018-01-10T20:16:52Z")
There are different common problems in control valves. Here we are going to discuss such problems: 1. Mechanical friction: Moving parts of control valves can be subjected to friction, primarily between the valve stem … --- ## [Interview Question - Explain modbus protocol concept?](https://forumautomation.com/t/interview-question-explain-modbus-protocol-concept/1234)
**Author:** [@automate](https://forumautomation.com/u/automate)\ **Replies:** 1\ **Last updated:** [August 13, 2016, 3:47pm UTC](https://forumautomation.com/t/interview-question-explain-modbus-protocol-concept/1234 "2016-08-13T15:47:24Z")
Modbus Protocol Concept 1.Master/Slave relationship Master sends a request to the slave Slave replies to the master requests Message contains device address (Slave id),Function code,Data,Error check 3.Each slave mu… --- ## [SCADA engineer interview question?](https://forumautomation.com/t/scada-engineer-interview-question/484)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [August 23, 2015, 11:51pm UTC](https://forumautomation.com/t/scada-engineer-interview-question/484 "2015-08-23T23:51:14Z")
SCADA programmer interview questions What is the full form of SCADA ? Supervisory control and Data Acquisition 2.What are the common system components of SCADA system ? Remote terminal units PLC Telemetry system Dat… --- ## [What are Flanges? Types of Flanges](https://forumautomation.com/t/what-are-flanges-types-of-flanges/4590)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [September 8, 2018, 3:16pm UTC](https://forumautomation.com/t/what-are-flanges-types-of-flanges/4590 "2018-09-08T15:16:05Z")
What are Flanges? A flange is an external or internal rib used for connecting pipes, valves and other equipment to frame a piping system. A flange is to strength or attachment to another object, as the flange on the end … --- ## [What is SI unit?](https://forumautomation.com/t/what-is-si-unit/2221)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 1\ **Last updated:** [August 20, 2017, 5:21am UTC](https://forumautomation.com/t/what-is-si-unit/2221 "2017-08-20T05:21:00Z")
What is SI unit? International system of unit (SI) is world’s most used system of measurement. International system of unit (abbreviated SI) is used officially in all countries except USA,Myanmar and Liberia. It has s… --- ## [What are the Important interview queations about Control valve?](https://forumautomation.com/t/what-are-the-important-interview-queations-about-control-valve/2403)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [October 7, 2017, 1:28pm UTC](https://forumautomation.com/t/what-are-the-important-interview-queations-about-control-valve/2403 "2017-10-07T13:28:19Z")
What is a control valve? A control valve is a final control element used to control fluid flow by varying the size of fluid passage in response to the signals received from controllers. Control valves are used to contro… --- ## [Control valve interview questions and answer](https://forumautomation.com/t/control-valve-interview-questions-and-answer/5632)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [January 2, 2019, 1:56pm UTC](https://forumautomation.com/t/control-valve-interview-questions-and-answer/5632 "2019-01-02T13:56:41Z")
What is a Control valve? A control value is the final control element, which directly changes the valve of the manipulated variable by changing the flow rate of the control agent. A control valve consists of an op… --- ## [What is process variable and types of process variables?](https://forumautomation.com/t/what-is-process-variable-and-types-of-process-variables/2818)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [December 14, 2017, 9:51pm UTC](https://forumautomation.com/t/what-is-process-variable-and-types-of-process-variables/2818 "2017-12-14T21:51:22Z")
Instruments are used to monitor and control a process to keep the process within a correct limit. The parameters or quantities that we wish to control at the correct limit are called Process Variables.A variable is some… --- ## [What are the two categories of Field Instrument transmitters?](https://forumautomation.com/t/what-are-the-two-categories-of-field-instrument-transmitters/1610)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [December 31, 2016, 6:02am UTC](https://forumautomation.com/t/what-are-the-two-categories-of-field-instrument-transmitters/1610 "2016-12-31T06:02:20Z")
Instrument transmitters are split in to two broad categories. 1.Loop Powered Instruments. Loop powered instruments are instrument with two wire connection to controller (PLC /DCS/ Stand Alone controller). Two wire con… --- ## [What is split range control system?](https://forumautomation.com/t/what-is-split-range-control-system/1431)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [October 12, 2016, 5:49am UTC](https://forumautomation.com/t/what-is-split-range-control-system/1431 "2016-10-12T05:49:53Z")
Split range control system or Duplex Control Split range controller has one input and two output. Split control divides the controller output in to two distinct functions. Heat/Cool controllers are one example of spli… --- ## [What is On-Delay and Off Delay timer](https://forumautomation.com/t/what-is-on-delay-and-off-delay-timer/1750)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [February 12, 2017, 4:52pm UTC](https://forumautomation.com/t/what-is-on-delay-and-off-delay-timer/1750 "2017-02-12T16:52:38Z")
Timer are used in PLC program to introduce some delays in a logic transition. On-Delay Timer For an On-delay timer two different types of contact. NOTC - Normally opened,timed -closed. This timer is normally open and… --- ## [Basic terms commonly used in instrumentation and its definition](https://forumautomation.com/t/basic-terms-commonly-used-in-instrumentation-and-its-definition/2483)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [October 20, 2017, 3:03pm UTC](https://forumautomation.com/t/basic-terms-commonly-used-in-instrumentation-and-its-definition/2483 "2017-10-20T15:03:49Z")
INSTRUMENTATION: A complete set of instruments combinedly used to control a process like production, refining. INSTRUMENTS: Devices that are used for measuring, indicating, controlling, recording can be considered as … --- ## [Electric machine interview question](https://forumautomation.com/t/electric-machine-interview-question/5032)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [October 27, 2018, 2:56pm UTC](https://forumautomation.com/t/electric-machine-interview-question/5032 "2018-10-27T14:56:29Z")
1.The unit of the rate at which energy is expended? Watt 2. What is a tap‐changing transformer? It is a transformer that has one or more leads wire output so the switch can be used to change the output voltage from a … --- ## [Power Plant Instrumentation engineer Interview Question](https://forumautomation.com/t/power-plant-instrumentation-engineer-interview-question/666)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 2\ **Last updated:** [December 14, 2015, 1:39am UTC](https://forumautomation.com/t/power-plant-instrumentation-engineer-interview-question/666 "2015-12-14T01:39:47Z")
Interview Questions and Answers : Power Plant Instrumentation and Electrical Engineers Name the four major circuits in steam power plant. • Coal and ash circuit • Air and flue gas circuit • Feed water and steam circui… --- ## [Why Is Reduced Trim Required In Control Valves?](https://forumautomation.com/t/why-is-reduced-trim-required-in-control-valves/4557)
**Author:** [@rajeena](https://forumautomation.com/u/rajeena)\ **Replies:** 0\ **Last updated:** [September 5, 2018, 3:37pm UTC](https://forumautomation.com/t/why-is-reduced-trim-required-in-control-valves/4557 "2018-09-05T15:37:52Z")
Why Is Reduced Trim Required In Control Valves? What Is The Trim In A Control Valve? The trim of the control valve is the parts that are in direct contact with the fluid that is controlled. The edge of the valve consists… --- ## [What are the advantages & disadvantages of PLC?](https://forumautomation.com/t/what-are-the-advantages-disadvantages-of-plc/2430)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [October 11, 2017, 4:14pm UTC](https://forumautomation.com/t/what-are-the-advantages-disadvantages-of-plc/2430 "2017-10-11T16:14:12Z")
Advantages: Small physical size & shorter project time. Cost effective for controlling complex system. Reliability. Less and simple wiring. Faster response. Remote control capability. More flexibility… --- ## [Electrical engineer Interview Question and Answer for Power Plant?](https://forumautomation.com/t/electrical-engineer-interview-question-and-answer-for-power-plant/994)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 1\ **Last updated:** [April 16, 2016, 7:12am UTC](https://forumautomation.com/t/electrical-engineer-interview-question-and-answer-for-power-plant/994 "2016-04-16T07:12:30Z")
Electrical Engineering Interview Question and Answer 1.Why use the vcb at high transmission system ? why cant use ACB? Actually the thing is vacuum has high arc quenching property compare to air because in VCB,the DIE … --- ## [Common Interview Questions: Industrial Automation](https://forumautomation.com/t/common-interview-questions-industrial-automation/140)
**Author:** [@instrumen](https://forumautomation.com/u/instrumen)\ **Replies:** 4\ **Last updated:** [June 3, 2017, 9:49am UTC](https://forumautomation.com/t/common-interview-questions-industrial-automation/140 "2017-06-03T09:49:06Z")
1.Explain Cascade Control system with a diagram. What would happier if a single controller were used ? 2. Explain ratio control system. 3. Explain fuel to air ratio control of furnaces. 4. What is Furnace Draft control ?… --- ## [What is Instrumentation Current loop and What are the advantages of Instrument current loop?](https://forumautomation.com/t/what-is-instrumentation-current-loop-and-what-are-the-advantages-of-instrument-current-loop/1349)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [September 14, 2016, 12:35am UTC](https://forumautomation.com/t/what-is-instrumentation-current-loop-and-what-are-the-advantages-of-instrument-current-loop/1349 "2016-09-14T00:35:24Z")
Instrumentation Current Loop (4-20 ma loops) Why to use 4-20 ma loops ? What are the advantages of 4-20 ma? The DC current loop is used extensively in the instrumentation field to transmit process variable to indica… --- ## [What are the advantages of using an instrumentation amplifier over an ordinary differential amplifier?](https://forumautomation.com/t/what-are-the-advantages-of-using-an-instrumentation-amplifier-over-an-ordinary-differential-amplifier/4558)
**Author:** [@rajeena](https://forumautomation.com/u/rajeena)\ **Replies:** 1\ **Last updated:** [April 26, 2019, 6:41am UTC](https://forumautomation.com/t/what-are-the-advantages-of-using-an-instrumentation-amplifier-over-an-ordinary-differential-amplifier/4558 "2019-04-26T06:41:48Z")
What are the advantages of using an instrumentation amplifier over an ordinary differential amplifier, in measuring low signals and voltages? What is the instrumentation amplifier? An instrumentation (or instrumentation)… --- ## [Calibration technician interview question?](https://forumautomation.com/t/calibration-technician-interview-question/487)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 1\ **Last updated:** [August 20, 2017, 12:49am UTC](https://forumautomation.com/t/calibration-technician-interview-question/487 "2017-08-20T00:49:59Z")
Top Interview questions : Calibration engineer / Calibration technician 1.What is the purpose of Calibration ? 2.What is traceability ? 3.What is span ? 4.What is range ? 5.Explain about zero suppression / elevation… --- ## [PLC interview questions](https://forumautomation.com/t/plc-interview-questions/3366)
**Author:** [@sivaranjith](https://forumautomation.com/u/sivaranjith)\ **Replies:** 0\ **Last updated:** [April 2, 2018, 5:24pm UTC](https://forumautomation.com/t/plc-interview-questions/3366 "2018-04-02T17:24:38Z")
1. What is PLC? Answer: PLC means Programmable Logic Controller. It is a class of industrially hardened devices that provides hardware interface for input sensors and output control element. The field I/p include elemen… [Next page](https://forumautomation.com/c/interview-questions-and-answers/32.md?page=1&per_page=50)