Description : A pattern displayed by oscilloscopes which has a steady characteristic is called
Last Answer : Lissajous
Description : The ___ provides the visual display showing the form of the signal applied as a waveform on the front screen of a cathode ray oscilloscope
Last Answer : CRT
Description : A device or instrument able to generate noise with accurate voltage for test purposes
Last Answer : noise generator
Description : For a dynamometer to be able to measure high current, a ___ should be used.
Last Answer : current transformer
Description : The original colour of beverages for longer period are retained by
Last Answer : Ans. Benzoic acid
Description : A certain pulse measures 10ms and has a period of 50ms. The duty cycle is __
Last Answer : 10ms/50ms = 20%
Description : The period of a repetitive signal is
Last Answer : 1 cycle of the waveform
Description : Private network can be a richear sorce of digital evidence than they internet (a) They retain data for longer period of time (b) Owener of private network more cooprative with law enforcement (c) Private network contain higher concentration of digital evidence (d) None of these
Last Answer : c) Private network contain higher concentration of digital evidence
Description : What is transistor ? What are the different types ?
Last Answer : A transistor is a three lagged semi conductor device. Basically a transistor means (transfer - resister). Whether the transistor is pnp or npn it resembles two diodes (back to back). The one of the left ... transistor : Emitter - Base - Forward Bias. Collector - Base - Reverse Bias.
Description : What are the different types of orifice plates and state their uses ?
Last Answer : The different types of orifice plates are : • Concentric. • Segmental. • Eccentric. • Quadrant Edge.
Description : What connector is popular in attaching test instruments like oscilloscopes, frequency counters, spectrum analyzers, etc? A. UHF connector B. PL-259 C. BNC D. SMA
Last Answer : C. BNC
Description : Oscilloscopes are used to measure what quantities?
Last Answer : Amplitude, phase, time, and frequency.
Description : List the circuits that all oscilloscopes have in common.
Last Answer : A CRT, a group of control circuits, power supply, sweep circuitry, and deflection circuitry.
Description : “Nationalism no longer retained its idealistic liberal democratic sentiment by the last quarter of the nineteenth century in Europe.” Analyse the statement with examples. -SST 10th
Last Answer : Nationalism in Europe- The Balkans: . During this period nationalist groups become increasingly intolerant of each other. . Manipulations of the nationalist aspirations were there. . The Balkan was under the control ... . This led to a series of wars in the region and finally the First World War.
Description : “Nationalism no longer retained its idealistic liberal democratic sentiment by the last quarter of the nineteenth century in Europe.” -SST 10th
Last Answer : Sentiment of Nationalism in the first half of the 19th century: (i) Towards the last quarter of the 19th century, nationalism could not retain its idealistic liberal-democratic sentiment of the ... to define their identity and independence, the Balkan area became an area of intense conflict.
Description : What type of sensing element would you use to measure very low temperature ?
Last Answer : The sensing element used for measuring very low temperature is R. T. D. ( Resistance Temperature Detector )
Description : The only use of voltage senstive meter movement
Last Answer : very low voltage measurement
Description : What is a filter used for ?
Last Answer : The half wave and full wave signals are pulsating D . C . voltages. The use of such voltages is limited to charging batteries, running D. C. motors, and a few other applications. What we really ... voltage from a battery. To get a constant voltage from this, we can use a capacitor input filter.
Description : What is Zener Diode ? What is a voltage Regulator ?
Last Answer : The breakdown region of a p n diode can be made very sharp and almost vertical Diodes with almost vertical breakdown region are known as Zever Diodes. A Zener diodes operating in the breakdown ... VOLTAGE REGULATOR : The output remains constant despite changes in input voltage due to Zever effect.
Description : What is CB, CE and CC configuration ?
Last Answer : Buffer : A device or a circuit used to isolate two pt'ne circuits or stages. The emitter follows is a example of buffer. Alpha = IC / IE Beta = IC / IB
Description : How will you test a transistor with a multimeter. ?
Last Answer : 1. Emitter +ve of meter and Base -ve output = Low resistance 2. Emitter -ve of meter and base +ve output = High resistance. 3. Collector +ve and Base -ve output = Low. 4. Collector -ve and base +ve output = High. Emitter : Collector = High Resistance. PNP : Opposite Results.
Description : What is a thyristor ? What are its uses ?
Last Answer : A thyristor is a special kind of semi conductor device that uses internal feedback to produce latching action. Use : Used for controlling large amounts of load power in motors, heaters, lighting systems etc ... the latches like a open switch. This latch will always stay in open or close position.
Description : What does a transmitter output start from 3-15 psi or (0.2 - 1 Kg/Cm2) or 4 - 20 ma. etc. ?
Last Answer : The transmitter output stance from what is known as "live zero". This system has specific advantages : 1. The systems automatically alarms when the signal system becomes inoperative. ... transmitter operating, but transmitting a zero measurement and a failure, in the signal system.
Description : What are Intrinsically safe system ?
Last Answer : Intrinsic safety is a technique for designing electrical equipment for safe use in locations made hazardous by the presence of flammable gas or vapors in air. "Defn. :" Intrinsically safe circuit is ... , unfortunately, been adopted in all countries. However two sets of codes in common use are.
Description : What is feed back control ? What is feed forward control ? Discuss its application ?
Last Answer : Feed back control: Feed back control involves the detection of the controlled variable and counteracting of charges its it's value relative to set point, by adjustment of a manipulated ... controller for a particular process application, two factors time and gain must be considered.
Description : What is Furnace Draft control ?
Last Answer : Balanced draft boilers are generally used negative furnace pressure. When both forced draft and induced draft are used together, at some point in the system the pressure will be the same as that of atmosphere. ... have is a very slight (about 0.1" H20 ) negative pressure of the top of furnace.
Description : What is the difference the a wheatstone bridge and a potentiometer ?
Last Answer : The difference between a potentiometer and a wheatstone bridge measuring instrument is that potentiometer is a voltage measuring instrument and wheatstone bridge is a current measuring instrument.
Description : What is the specialty of thermocouples lead wires ?
Last Answer : They should be of the same material as the thermocouple.
Description : What are skin temperature thermocouples ?
Last Answer : Skin thermocouples are those which are directly connected to the process without any thermowell. Used for measuring the skin temperature of heaters furnaces, flue gas etc.
Description : How will you calibrate a temp. recorder using a potentiometer ?
Last Answer : Connect the potentiometer output to the input of temp. recorder. 1. Connect the ( +ve ) to the ( +ve ) and ( -ve ) to the ( -ve ). 2. If ambient compensation is provided ... ambient temp. millvolts to the corr. input millvolts measured. Find out from the chart for the corresponding temperature.
Description : Why are Thermowells used ?
Last Answer : In numerous application it is neither desirable nor practical to expose a temperature sensor directly to a process material. Wells are therefore used to protect against damage corrosion, erosion, abrasion and high pressure processes. A ... 3. Monel. 4. Alloy steal. 5. Hastelloy 'C'.
Description : Why is a converter used in a temp. recorder ?
Last Answer : The converter is designed to convert D. C. input voltage into an A. C. input voltage proportional in amplitude to the input.
Description : What is burnout feature ? Explain.
Last Answer : Burnout provides the warning feature of driving indicator the end of scale if the input circuit should open. A burnout resistor is provided which develops a voltage drop between the measuring circuit and the ... Upscale burnout : R value 10 M Downscale burnout : R value 2.2 M
Description : What is the constant voltage unit ?
Last Answer : The constant voltage circuit consists of a rectifier, CR, a filter capacitor C1, followed by two stages of zener regulation. Abridge configuration is provided to 1amp line voltage regulation ... , Thus variations. Resisters R2 and R3 form a bridge that any remoment line voltage effects.
Description : Draw a potentiometer temp. Measuring circuits and explain its?
Last Answer : OPERATION : The input to the instrument is a measurement of some in the processes using a sensing element ( such as thermocouple ) or a device to produce direct voltage, which is the voltage (signal) ... to zero results ( null point ) the balancing ( servo motor is be longer driven )
Description : What is two wire and three wire R.T.D. system ?
Last Answer : Two wire R .T .D. system : Two wire RTD system use for short distance like a compressor field local panel. Three wire System : Three wire system use for long distance coke a field to control Run. The third wire is used for compensation of lead wire resistance.
Description : What is Pt 100 mean. ?
Last Answer : Pt100 means 100 OHMS at 0'C for a platinum resistance bulb.
Description : Explain the working of an Enraf level gauge?
Last Answer : The Enraf precise level gauge are based on servo powered null-balance technique. A displacer serves as a continuous level sensing element. Principle: A displacer with a relative density higher than ... to a remote indicator of which the receiver motor drives a counter indicating level variation.
Description : How will you check zero of a level D.P. transmitter while is line ?
Last Answer : ١. Close both the isolation valves. ٢. Open the vent valve on L.P. leg and H.P. leg drain. ٣. Check and adjust zero if necessary.
Description : How will you commission D.P. transmitter in field in pressurized vessel.
Last Answer : ١. Close both the isolation valves, Vent the H.P. side. ٢. Fill it with the sealing liquid. ٣. Open the L.P. side vent valve. ٤. Adjust zero with suppression spring. ٥. Close the L.P. side vent valve. ٦. Open both the isolation valves.
Description : What are the limitations of leveltrol ?
Last Answer : The limitations of a level control that it cannot be used for lengths more than 72 inches.
Description : What is the used of Suppression and elevation ?
Last Answer : Suppression and elevation are used on Level applications where (1) transmitters are not mounted on some level (2) Wet leg. i.e. condensable vapors are present.
Description : What will happen if the displacer has a hole in it while in line ?
Last Answer : The output will be minimum.
Description : What will happen if the displacer has fallen down while in line ?
Last Answer : The output will be maximum.
Description : How will you calibrate a leveltrol in the field ?
Last Answer : Calculation # 1 If the calibrating liquid is water: Process Liquid Density / 1* Displacer height = mm of H2O. Calculation # 2 If the calibrating liquid is Other liquid: Process Liquid Density / ... gravity or span adjustment ( Electronic Level ). 6. Fill it up to 50 %, check linearity.
Description : What is interface level ? How do you calculate it ?
Last Answer : When a vessel is filled with two liquids of two different specific gravities the level measurement refers to as interface level. DP = H ( D - d ) On a level set the difference of two specific gravities.
Description : How will you reverse an action of the leveltrol.?
Last Answer : The reversing are serves as motion take off arm from the torque tube. It is provided with a slot on each side of the center so that link can be connected either for reverse or direct action.
Description : Explain the working an electronic leveltrol.
Last Answer : The variation in buoyancy resulting from a change in liquid level, varies the net weight of the displacer increasing or decreasing the load on the torque arm. This change is directly ... change proportional to the rotor displacement, which is converted and amplified to a D.C. current.
Description : Explain the working of a leveltrol.
Last Answer : The leveltrol is used for measuring level of liquids in a closed vessel. ١. PRINCIPLE. : It works on Archimedes principle "The loss in weight of a body immersed in a liquid is equal to ... proportional output air pressure. ٦. CONTROL SETTING UNIT : Provides a motions of varying the set point.
Description : What is purge level system ?
Last Answer : This method is also known as bubbler method of level measurement. A pipe is installed vertically with its open end at the zero level. The other end of the pipe is connected to a regulated ... liquids where the transmitter cannot be directly connected to process eg... Acids, Some organic liquids.