What are Intrinsic Safety Barriers? Answer: The safety barriers for the zener diode are voltage regulators. There are two different types of barriers, one way and two-way barriers. There are two types of safety barriers: Active barriers Passive barrier

Instrumentation Cables  1. What is the difference between IS and non IS cables? Non IS cables are used in non-hazardous areas where protection needs no special consideration. Cables that are safe in faulty situations, protected from external electrical or magnetic field damage and used in intrinsic circuits are referred to as intrinsically safe cables or IS cables. 2. What differs Intrinsic earthing from usual earthing? The IS ground connection must be separated from plant earth and other electrical ground. When used in IS cables, the screens should only be grounded at one point, usually at the same point where the interface devices are grounded, and should be isolated from each other 3. What is intrinsic safety system? A system that involves equipment and interconnecting wiring in which any spark or thermal effect in any part of the system intended for use in hazardous areas is unable to cause ignition. 4. What are Intrinsic Safety Barriers? The safety barriers for the zener diode are

What are the requirements for carrying out installation inspection of any instrument? Answer: The following are the requirements at the time of execution of an inspection. Instrument datasheet. Instrument Test Certificate. Vendor instruction manual. Test Instrument instruction manual

What items inspection to be done for instrument Stand and supports? Answer: Fabrication of stand as per the drawing Deburred, primed and painted. Stand and support are secure. Stand ground point. Access to stand is unobstructed and clear for maintenance.

What are the responsibilities of the QC Inspector? Answer: The following are the extraordinary responsibilities that any QC Inspector is supposed to execute at the time of carrying out any inspection. Knowledgeable with the technology for which the inspection is carried out. Should have the reasoning capability to analyze the method. Should have in-depth knowledge about the procedure to be adopted for inspection i.e. adopted standards. Should be able to convey the irregularities found to the concerned authorities such as QC Engineer or QC Manager. Should be sincere about the job execution. Should be vigilant all the time.

Quality Control Inspector Interview Questions and Answers 1. What is an Inspection? Answer: It is a process of verifying the method and application utilizing by means of following certain documented and authenticated instruction standards are known as inspection Quality Assurance Program Installation Pre-Installation Verification Installation Process Control After Installation Verification Turnover for Commissioning 2. What are the responsibilities of the QC Inspector? Answer: The following are the extraordinary responsibilities that any QC Inspector is supposed to execute at the time of carrying out any inspection. Knowledgeable with the technology for which the inspection is carried out. Should have the reasoning capability to analyze the method. Should have in-depth knowledge about the procedure to be adopted for inspection i.e. adopted standards. Should be able to convey the irregularities found to the concerned authorities such as QC Engineer or QC Manager. Should be sincere about

Root Locus Effect of Addition of zeros Addition of zeros The addition of a zero to the open-loop transfer function has the effect of pulling the root locus to the left, tending to make the system more stable and to speed up the settling of the response.  Physically, the addition of a zero in the feed forward transfer function means the addition of derivative control to the system. The effect of such control is to introduce a degree of anticipation into the system and speed up the transient response. The Figure 1(a) shows the root loci for a system that is stable for small gain but unstable for large gain.  Figures 1(b), (c), and (d) show root-locus plots for the system when a zero is added to the open-loop transfer function. It becomes stable for all values of gain. However, it is not possible to add an isolated zero to a transfer function because of physical non-realizability. Therefore, in order to realize the compensating network a pair of pole-zero has to be incorporated.

1. Which operator is the most important while assigning any instruction as register indirect instruction? a) $ b) # c) @ d) & Answer: @ 2. Which of the following comes under the indexed addressing mode? a) MOVX A, @DPTR b) MOVC @A+DPTR,A c) MOV A,R0 d) MOV @R0,A Answer: MOVC @A+DPTR,A

Multiple choice Questions and Answers on Heat exchanger 1. Water (specific heat = 4 k J/kg K) enters a cross flow exchanger (both fluids unmixed) at 15 degree Celsius and flows at the rate of 7.5 kg/s. It cools air (C P = 1 k J/kg K) flowing at the rate of 10 kg/s from an inlet temperature of 120 degree Celsius. For an overall heat transfer coefficient of 780 k J/m2 hr degree and the surface area is 240 m2, determine the NTU a) 4.2 b) 5.2 c) 6.2 d) 7.2 Answer: 5.2 2. Consider the above problem, find the capacity ratio of the heat exchanger a) 0.555 b) 0.444 c) 0.333 d) 0.222 Answer: 0.333 3. The engine oil at 150 degree Celsius is cooled to 80 degree Celsius in a parallel flow heat exchanger by water entering at 25 degree Celsius and leaving at 60 degree Celsius. Estimate the exchanger effectiveness a) 0.56 b) 0.66 c) 0.76 d) 0.86 Answer: 0.56 4. In a surface condenser, the water flowing through a series of tubes at the rate of 200 kg/hr is heated from 15 degree Celsius to 75 degree Ce

Process Control and Instrumentation 1. What Is Process Control Instrumentation? Answer: Process control instrumentation focuses on the measurement and control of process variables within an industrial setting using hardware and software tools. Control systems are derived from mathematical models of industrial processes and systems. 2. Why Is Instrumentation and Process Control Essential? Answer: Instrumentation and process control is at the core of all industrial and manufacturing activities. Within a production facility, every process must be carefully monitored and controlled to proceed in a predetermined fashion that is both optimized and safe. For example, temperature monitoring and control systems at petrochemical plants prevent temperatures from rising to critical levels and causing an explosion. Without electric process heater control panels, there could be a loss of human lives and the destruction of assets. 3. Industries that Need Instrumentation and Process Control Virtually

Calibration  Question and Answer 1. What is calibration? Calibration is a set of operations that documented comparison of the measurement device to be calibrated against a traceable reference standard/device. 2. What is calibration certificates? The calibration certificate is the official document authorized for the calibration of instruments and provides traceability to the National Institute of Standards and Technology. The calibration certificate is issued by most businesses as a historical record. However, some enter data on the certificate in a local database to track the status of their test equipment inventory. 3. What is the difference between a Standard (Traceable) and Accredited Calibration Certificate? Standard (Traceable) Certificate: Instrumentation is calibrated to specifications with traceable standards. A full data report is optional with the calibration certificate. Accredited Certificate: meets the ISO / IEC 17025 requirements and the accrediting body of the laborator

Differential Pressure Flow Meters Differential pressure flow meters use laminar plates, an orifice, nozzle, or Venturi tube to create an artificial constriction then measure the pressure loss of fluids as they pass that constriction. According to Bernoulli's principle, the pressure drop across the constriction is proportional to the square of the flow rate. The higher the pressure drop, the higher the flow rate. These rugged, accurate meters are ideal for a wide range of clean liquids and gases. What is a differential Pressure (Δp) meter? Differential pressure meters work on the principle of partially obstructing the flow in a pipe. This creates a difference in the static pressure between the upstream and downstream side of the device. This difference in the static pressure (referred to as the differential pressure) is measured and used to determine the flow rate. Differential-pressure meters are hugely popular and it is estimated that at least 40% of industrial flow meters in use

instrumentation Question and Answer 1. What Is Instrumentation? Answer: The technology which is used to measured and control the process system of plant is  called instrumentation. It is branch of engineering. 2. What is the instrumentation Engineering? Answer: Instrumentation engineering is the engineering specialization deals with principle and operation of measuring devices used in electrical, pneumatic, etc. design and configuration of automated systems. Instrumentation engineers work with automated processes, such as chemical or manufacturing plants, for industries to enhance system efficiency, reliability, health, optimization and stability. 3. What is the instrumentation measurement? Answer: Instrumentation can be used to measure certain field parameters (physical values): Pressure, either differential or static Flow Temperature measurement Level Measurement Density Viscosity Radiation Current Voltage Inductance Capacitance Frequency Resistivity Conductivity Chemical compositi

Flow Switch A flow switch is one detecting the flow of some fluid through a pipe. Flow switches often use “paddles” as the flow-sensing element, the motion of which actuates one or more switch contacts. A flow switch, like all switches, is a device designed to make and break an electric current in a circuit. In an industrial system, a flow switch is essential in monitoring and controlling the flow rate of process media – such as steam, liquids, and gases. Flow switches help maintain safe and manageable rates of flow by triggering actions in various machines within a system to provide on/off flow control of process media. Principle of Flow Switch The “normal” status of a switch is the resting condition of no stimulation. A flow switch will be in its “normal” status when it senses minimum flow (i.e. no fluid moving through the pipe). For a flow switch, “normal” status is any fluid flow rate below the trip threshold of the switch. Working of the flow switch  Firstly th

Multiple Choice Questions and Answers on Process Control and Instrumentation 1. The temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured by a/an __________ thermocouple. a) chromel-alumel b) iron-constantan c) platinum-platinum/rhodium d) none of these. Answer: iron-constantan 2. Flapper nozzle is used in a/an __________ controller. a) electronic b) hydraulic c) pneumatic d) none of these Answer: pneumatic 3. The __________ of a vapor pressure thermometer is a functioning element. a) pointer b) bourdon tube c) bulb d) none of these Answer: pointer 4. A negative gain margin expressed in decibels means a/an __________ system. a) stable b) unstable c) critically damped d) none of these Answer: unstable 5. Temperature measuring instruments are standardised mostly with __________ points of pure substances. a) melting b) boiling c) both (a) & (b) c) neither (a) nor (b) Answer: both (a) & (b) 6. Response of a system to a sinusoidal input

Multiple Choice Questions & Answers on 8051 I/O Port Programming and Addressing Modes 1. Auto reload mode is allowed in which mode of the timer? a) Mode 0 b) Mode 1 c) Mode 2 d) Mode 3 Answer: Mode 2 2. If Timer 0 is to be used as a counter, then at what particular pin clock pulse need to be applied? a) P3.3 b) P3.4 c) P3.5 d) P3.6 Answer: P3.4 3. What is the maximum delay that can be generated with the crystal frequency of 22MHz? a) 2978.9 sec b) 0.011 msec c) 11.63 sec d) 2.97 msec Answer: 2.97 msec 4. In the instruction “MOV TH1,#-3”, what is the value that is being loaded in the TH1 register? a) 0xFCH b) 0xFBH c) 0xFDH d) 0xFEH Answer: 0xFDH 5. TF1, TR1, TF0, TR0 bits are of which register? a) TMOD b) SCON c) TCON d) SMOD Answer: TCON 6. Find out the roll over value for the timer in Mode 0, Mode 1 and Mode 2? a) 00FFH,0FFFH,FFFFH b) 1FFFH,0FFFH,FFFFH c) 1FFFH,FFFFH,00FFH d) 1FFFH,00FFH,FFFFH Answer: 1FFFH,FFFFH,00FFH. 7. What is the clock source for the timers? a) some external

8051 microcontroller MCQ 1. ANL instruction is used _______ a) to AND the contents of the two registers b) to mask the status of the bits c) all of the mentioned d) none of the mentioned Answer: all of the mentioned 2. CJNE instruction makes _______ a) the pointer to jump if the values of the destination and the source address are equal b) sets CY=1, if the contents of the destination register are greater then that of the source register c) sets CY=0, if the contents of the destination register are smaller then that of the source register d) none of the mentioned Answer: none of the mentioned 3. XRL, ORL, ANL commands have _______ a) accumulator as the destination address and any register, memory or any immediate data as the source address b) accumulator as the destination address and any immediate data as the source address c) any register as the destination address and accumulator, memory or any immediate data as the source address d) any register as the destination address and any i

Multiple Choice Questions & Answers on 8051 Interfacing 1. An electronic device which converts physical quantity or energy from one form to another is called ______ a) Sensor b) Transistor c) Transducer d) Thyristor Answer: Transducer 2. A thermistor is a __________ a) sensor b) adc c) transducer d) micro controller Answer: transducer 3. DS12887 is a ____________ a) Timer IC b) Serial communication IC c) RTC IC d) Motor Answer: RTC IC 4. DS12887 has _____ amount of RAM. a) 14 bytes b) 114 bytes c) 128 bytes d) 64 bytes Answer: 128 bytes 5. The 8255 is a ______ chip. a) Input/Output b) Analog to Digital c) Digital to analog d) None of the mentioned Answer: Input/Output 6. DS12887 has _____ amount of RAM for general purpose applications. a) 9 bytes b) 114 bytes c) 128 bytes d) 14 bytes Answer: 114 bytes 7. How many pins of the 8255 can be used as the I/O ports? a) 8 b) 16 c) 24 d) 32 Answer: 24 8. LM35 has how many pins? a) 2 b) 1 c) 3 d) 4 Answer: 3 9. Find the control word for PA =

Types of Heat Exchanger Questions & Answers 1. Heat exchanger effectiveness is a) <1 b) =1 c) >1 d) None of the mentioned Answer: <1  2. In a cross flow heat exchanger, the angle between hot and cold fluids is a) 900 b) 1800 c) 800 d) None of the mentioned Answer: 900 3. In a counter flow heat exchanger, the angle between hot and cold fluids is a) 900 b) 1800 c) 800 d) None of the mentioned Answer: 1800 4. In condensers/boilers, heat capacity ratio is a) Infinity b) Zero c) 1 d) None of the mentioned Answer: Zero 5. Rate of heat transfer by condensing fluid is a) m.cp Δt b) m. LH c) m.Δt d) None of the mentioned Answer: m. LH 6. In case of a 1:1 heat exchanger, use a) LMTD b) NTU c) LMTD or NTU d) None of the mentioned Answer: LMTD or NTU 7. NTU in a heat exchanger is a) UA/C b) C min/UA c) UA/C max d) None of the mentioned Answer: None of the mentioned 8. ‘C’ heat capacity ratio in a heat exchanger be a) =1 b)  > 1 c) >4 d) None of the mentioned Answer: None of the