# \#interviewquestions **URL:** https://forumautomation.com/tag/interviewquestions/6.md [Latest](https://forumautomation.com/latest.md) · [Categories](https://forumautomation.com/categories.md) · [Tags](https://forumautomation.com/tags.md) --- ## [What is hysteresis in control valves?](https://forumautomation.com/t/what-is-hysteresis-in-control-valves/14486)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 30, 2026, 3:52pm UTC](https://forumautomation.com/t/what-is-hysteresis-in-control-valves/14486 "2026-10-30T15:52:14Z")
\*\*What is hysteresis in control valves?\*\* --- ## [What is the difference between ex-e and ex-d protection?](https://forumautomation.com/t/what-is-the-difference-between-ex-e-and-ex-d-protection/14560)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 30, 2026, 3:50pm UTC](https://forumautomation.com/t/what-is-the-difference-between-ex-e-and-ex-d-protection/14560 "2026-10-30T15:50:14Z")
What is the difference between ex-e and ex-d protection? --- ## [What is the difference between fat and fwt?](https://forumautomation.com/t/what-is-the-difference-between-fat-and-fwt/14559)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 30, 2026, 3:48pm UTC](https://forumautomation.com/t/what-is-the-difference-between-fat-and-fwt/14559 "2026-10-30T15:48:03Z")
What is the difference between fat and fwt? --- ## [What is ATEX and EX classification?](https://forumautomation.com/t/what-is-atex-and-ex-classification/14561)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 0\ **Last updated:** [October 30, 2026, 1:19pm UTC](https://forumautomation.com/t/what-is-atex-and-ex-classification/14561 "2026-10-30T13:19:15Z")
What is ATEX and EX classification? --- ## [What is the first step in diagnosing a problem with PLC inputs?](https://forumautomation.com/t/what-is-the-first-step-in-diagnosing-a-problem-with-plc-inputs/14558)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 0\ **Last updated:** [October 30, 2026, 1:15pm UTC](https://forumautomation.com/t/what-is-the-first-step-in-diagnosing-a-problem-with-plc-inputs/14558 "2026-10-30T13:15:09Z")
What is the first step in diagnosing a problem with PLC inputs? --- ## [Why is Hipot Testing important for 11 kV Cables?](https://forumautomation.com/t/why-is-hipot-testing-important-for-11-kv-cables/13565)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 23, 2025, 12:22pm UTC](https://forumautomation.com/t/why-is-hipot-testing-important-for-11-kv-cables/13565 "2025-09-23T12:22:50Z")
Why is Hipot Testing important for 11 kV Cables? \[color=#21855c\] Hipot Test \[/color\] The \[url= What is Hipot Testing? Explain the Step-by-Step Procedure for Hipot Testing (Dielectric Strength Test)\]\[color=#1E00A3\] Hipot … --- ## [Why does a Healthy 3-Phase System Have Positive Sequence?](https://forumautomation.com/t/why-does-a-healthy-3-phase-system-have-positive-sequence/14531)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 23, 2026, 12:42pm UTC](https://forumautomation.com/t/why-does-a-healthy-3-phase-system-have-positive-sequence/14531 "2026-10-23T12:42:20Z")
Why does a Healthy 3-Phase System Have Positive Sequence? In a balanced three-phase power system, the three phase currents have equal magnitudes, a 120° phase displacement, and the correct phase rotation. This is known a… --- ## [What are the different types of intrinsically safe barriers?](https://forumautomation.com/t/what-are-the-different-types-of-intrinsically-safe-barriers/14489)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 22, 2026, 4:54pm UTC](https://forumautomation.com/t/what-are-the-different-types-of-intrinsically-safe-barriers/14489 "2026-10-22T16:54:03Z")
What are the different types of intrinsically safe barriers? --- ## [What are the common causes of control valve failure?](https://forumautomation.com/t/what-are-the-common-causes-of-control-valve-failure/14487)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 22, 2026, 4:52pm UTC](https://forumautomation.com/t/what-are-the-common-causes-of-control-valve-failure/14487 "2026-10-22T16:52:40Z")
What are the common causes of control valve failure? --- ## [What is Modbus TCP/IP?](https://forumautomation.com/t/what-is-modbus-tcp-ip/14492)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 22, 2026, 4:50pm UTC](https://forumautomation.com/t/what-is-modbus-tcp-ip/14492 "2026-10-22T16:50:26Z")
What is Modbus TCP/IP? --- ## [How do transmission lines carry low current but high voltage?](https://forumautomation.com/t/how-do-transmission-lines-carry-low-current-but-high-voltage/12225)
**Author:** [@NicholasDeo](https://forumautomation.com/u/NicholasDeo)\ **Replies:** 1\ **Last updated:** [June 28, 2024, 3:18pm UTC](https://forumautomation.com/t/how-do-transmission-lines-carry-low-current-but-high-voltage/12225 "2024-06-28T15:18:24Z")
How do transmission lines carry low current but high voltage? --- ## [What is the common problem in a control valve?](https://forumautomation.com/t/what-is-the-common-problem-in-a-control-valve/13675)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 2\ **Last updated:** [October 20, 2026, 4:12am UTC](https://forumautomation.com/t/what-is-the-common-problem-in-a-control-valve/13675 "2026-10-20T04:12:15Z")
What is the common problem in a control valve? --- ## [What is IP rating ? Why to use IP rating?](https://forumautomation.com/t/what-is-ip-rating-why-to-use-ip-rating/1014)
**Author:** [@denizen](https://forumautomation.com/u/denizen)\ **Replies:** 0\ **Last updated:** [April 28, 2016, 12:31am UTC](https://forumautomation.com/t/what-is-ip-rating-why-to-use-ip-rating/1014 "2016-04-28T00:31:48Z")
IP rating - When designing a system we need to make certain the product selected is reliable with a long life.Part of that process is determining if the product is appropriate for the application environment. But what a… --- ## [Difference between EMF and Voltage](https://forumautomation.com/t/difference-between-emf-and-voltage/14507)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 15, 2026, 3:57pm UTC](https://forumautomation.com/t/difference-between-emf-and-voltage/14507 "2026-10-15T15:57:24Z")
Difference between EMF and Voltage EMF (Electromotive Force) and voltage are both measured in volts (V), but they represent different electrical concepts. EMF is the energy supplied by a source per unit charge while … --- ## [What is Arc Flash Analysis?](https://forumautomation.com/t/what-is-arc-flash-analysis/14505)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 15, 2026, 3:38pm UTC](https://forumautomation.com/t/what-is-arc-flash-analysis/14505 "2026-10-15T15:38:53Z")
What is Arc Flash Analysis? An arc flash occurs when an electrical fault causes current to flow through the air gap between conductors or between a conductor and ground. The resulting electrical arc releases intense … --- ## [What are the steps involved in planning a wirelessHART network?](https://forumautomation.com/t/what-are-the-steps-involved-in-planning-a-wirelesshart-network/14488)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 15, 2026, 4:06am UTC](https://forumautomation.com/t/what-are-the-steps-involved-in-planning-a-wirelesshart-network/14488 "2026-10-15T04:06:22Z")
What are the steps involved in planning a wirelessHART network? --- ## [What are the requirements for intrinsically safe?](https://forumautomation.com/t/what-are-the-requirements-for-intrinsically-safe/14490)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 15, 2026, 4:03am UTC](https://forumautomation.com/t/what-are-the-requirements-for-intrinsically-safe/14490 "2026-10-15T04:03:52Z")
What are the requirements for intrinsically safe? --- ## [What can I do to troubleshoot Modbus communication failure?](https://forumautomation.com/t/what-can-i-do-to-troubleshoot-modbus-communication-failure/14491)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 15, 2026, 4:00am UTC](https://forumautomation.com/t/what-can-i-do-to-troubleshoot-modbus-communication-failure/14491 "2026-10-15T04:00:41Z")
What can I do to troubleshoot Modbus communication failure? --- ## [Why is Reactive Power Essential in Power Systems?](https://forumautomation.com/t/why-is-reactive-power-essential-in-power-systems/14263)
**Author:** [@TSRS](https://forumautomation.com/u/TSRS)\ **Replies:** 3\ **Last updated:** [October 13, 2026, 4:45pm UTC](https://forumautomation.com/t/why-is-reactive-power-essential-in-power-systems/14263 "2026-10-13T16:45:11Z")
Why is Reactive Power Essential in Power Systems? Reference Image Provided by the Respondent --- ## [What is an MCC Panel? What are its Main Components?](https://forumautomation.com/t/what-is-an-mcc-panel-what-are-its-main-components/14501)
**Author:** [@TSRS](https://forumautomation.com/u/TSRS)\ **Replies:** 0\ **Last updated:** [October 13, 2026, 4:40pm UTC](https://forumautomation.com/t/what-is-an-mcc-panel-what-are-its-main-components/14501 "2026-10-13T16:40:42Z")
What is an MCC Panel? What are its Main Components? An MCC (Motor Control Center) panel is an assembly used to control, protect, and distribute power to multiple electric motors and their associated equipment in an indus… --- ## [What are the Common NFPA 70E Violations?](https://forumautomation.com/t/what-are-the-common-nfpa-70e-violations/13327)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [June 16, 2025, 4:50pm UTC](https://forumautomation.com/t/what-are-the-common-nfpa-70e-violations/13327 "2025-06-16T16:50:09Z")
Common NFPA 70E Violations: 1). Failure to do an Arc Flash Risk Assessment 2). Inadequate or non-rated apparel in Arc Flash Zones 3). Working with Energized Equipment without Justification 4). Lack of Training 5). … --- ## [Transformer Parallel Operation](https://forumautomation.com/t/transformer-parallel-operation/14494)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 9, 2026, 4:00pm UTC](https://forumautomation.com/t/transformer-parallel-operation/14494 "2026-10-09T16:00:38Z")
Transformer Parallel Operation --- ## [What Are the Four Types of SCADA Systems?](https://forumautomation.com/t/what-are-the-four-types-of-scada-systems/14464)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 9, 2026, 5:17am UTC](https://forumautomation.com/t/what-are-the-four-types-of-scada-systems/14464 "2026-10-09T05:17:54Z")
What Are the Four Types of SCADA Systems? --- ## [What is the difference between ESD and DCS?](https://forumautomation.com/t/what-is-the-difference-between-esd-and-dcs/14462)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 9, 2026, 5:11am UTC](https://forumautomation.com/t/what-is-the-difference-between-esd-and-dcs/14462 "2026-10-09T05:11:13Z")
ESD vs DCS: Differences, Functions and Industrial Applications --- ## [SCADA vs BMS: Key Differences, Applications and Selection](https://forumautomation.com/t/scada-vs-bms-key-differences-applications-and-selection/14465)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 9, 2026, 5:07am UTC](https://forumautomation.com/t/scada-vs-bms-key-differences-applications-and-selection/14465 "2026-10-09T05:07:08Z")
SCADA vs BMS: Key Differences, Applications and Selection --- ## [What is a Voltage Stabilizer?](https://forumautomation.com/t/what-is-a-voltage-stabilizer/13503)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 3, 2025, 5:22am UTC](https://forumautomation.com/t/what-is-a-voltage-stabilizer/13503 "2025-09-03T05:22:28Z")
\[color=#ff0000\] What is a Voltage Stabilizer? \[/color\] Voltage stabilizers serve an important equipment in ensuring the optimal performance and dependability of electrical & mechanical systems. These devices protect sen… --- ## [Top 10 Essential Electrical & Motor Troubleshooting Q&As for Engineers](https://forumautomation.com/t/top-10-essential-electrical-motor-troubleshooting-q-as-for-engineers/14467)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 2, 2026, 4:40pm UTC](https://forumautomation.com/t/top-10-essential-electrical-motor-troubleshooting-q-as-for-engineers/14467 "2026-10-02T16:40:40Z")
Top 10 Essential Electrical & Motor Troubleshooting Q&As for Engineers Whether you work in industrial maintenance, MEP projects, electrical commissioning, or motor control, understanding these fundamental troubleshooting… --- ## [What is Cage-guided Globe control Valve?](https://forumautomation.com/t/what-is-cage-guided-globe-control-valve/14466)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 2, 2026, 9:20am UTC](https://forumautomation.com/t/what-is-cage-guided-globe-control-valve/14466 "2026-10-02T09:20:18Z")
What is Cage-guided Globe control Valve ? --- ## [Which is better, DCS or SCADA?](https://forumautomation.com/t/which-is-better-dcs-or-scada/14463)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 2, 2026, 9:19am UTC](https://forumautomation.com/t/which-is-better-dcs-or-scada/14463 "2026-10-02T09:19:01Z")
Which is better, DCS or SCADA? --- ## [What is dust group IIIA, IIIB, IIIC?](https://forumautomation.com/t/what-is-dust-group-iiia-iiib-iiic/14449)
**Author:** [@Instrument\_Engineer](https://forumautomation.com/u/Instrument_Engineer)\ **Replies:** 1\ **Last updated:** [October 2, 2026, 9:17am UTC](https://forumautomation.com/t/what-is-dust-group-iiia-iiib-iiic/14449 "2026-10-02T09:17:11Z")
What is dust group IIIA, IIIB, IIIC? [Next page](https://forumautomation.com/tag/interviewquestions/6.md?match_all_tags=true&page=1&tags%5B%5D=interviewquestions)