1) Accuracy of a measuring instrument indicates thea. Closeness of the output reading to the true valueb. Ratio of output value to the input valuec. Change in output with each change in inputd. Degree of freedom from random errors

ANSWER: Closeness of the output reading to the true value

2) If a pressure gauge of range 0 - 10 bar has a quoted inaccuracy of ±1.0 % of full scale reading, then itmeansa. Minimum expected error in any reading is 0.1 barb. Maximum expected error in any reading is 0.1 barc. Maximum expected error in any reading is 1 bard. Minimum expected error in any reading is 1 bar

ANSWER: Maximum expected error in any reading is 0.1 bar

3) An instrument with a range of 0 -10 bar is used for measuring pressure. If the expected value ofreading is between 0 and 1 bar then the instrument will givea. More accurate readings than the instrument with range of 0 - 5 barb. Less accurate readings than the instrument with range of 0 - 5 barc. Accuracy of reading will be same for both the instruments with range of 0 - 10 bar and 0 - 5 bard. None of these

ANSWER: Less accurate readings than the instrument with range of 0 - 5 bar

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4) A voltmeter connected across a resistor gives a value of 65 V but the expected value of resistor was68 V. Then the absolute error and the relative accuracy of the measurement will bea. 3.2%, 96.8%b. 3.8%, 96.2%c. 4%, 96%d. 4.4%, 95.59%

ANSWER: 4.4%, 95.59%

5) Precision of an instrument is defined as a. Closeness of output to the true valueb. Change in output for every change in inputc. Degree of freedom from random errorsd. Both (a) and (b)

ANSWER: Degree of freedom from random errors

6) An instrument with high precision impliesa. High accuracyb. Low accuracyc. Does not imply anything about measurement accuracyd. None of these

ANSWER: Does not imply anything about measurement accuracy

7) Low accuracy measurements from a high precision instrument are normally caused by a. Bias in the measurementb. Human errorsc. Instrumental defectd. Low temperature

ANSWER: Bias in the measurement

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8) Choose the correct option.I. Repeatability means the closeness of output readings when the same input is applied repetitively over ashort period of time, with the same measurement conditions and same instruments.

II. Reproducibility means the closeness of output readings for the same input when there are changes inthe method of measurement and conditions of measurement

a. Both I and II are correctb. Only I is correctc. Only II is correctd. Both are incorrect

ANSWER: Both I and II are correct

9) Integrating instruments is the subdivision of the secondary instruments. The example for integratinginstruments isa. Ampere - hour metersb. Watt - hour metersc. Wattmetersd. Ampere - hour and watt - hour meters

ANSWER: Ampere - hour and watt - hour meters

10) The moving system in the indicating instruments is subjected toa. Deflecting torqueb. Controlling torquec. Damping torqued. All the abovee. None of the above

ANSWER: All the above

11) A spring controlled moving iron voltmeter with full scale deflection of 150 V draws a current of 2 mA.What will be the meter reading if it draws a current of 1 mA?a. 25.5 Vb. 27.5 Vc. 35.5 Vd. 37.5 V

ANSWER: 37.5 V

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12) A repulsion type moving iron instrument when used with AC circuits, the deflecting torque is a. Directly proportional to the rms currentb. Directly proportional to the square of rms currentc. Directly proportional to the peak currentd. Directly proportional to the square of the peak current

ANSWER: Directly proportional to the square of rms current

13) What will a moving iron ammeter read if a rectangular waveform current with peak value of 120 mA ispassed through it?a. 120 mAb. 84.8 mAc. 169.7 mAd. 60 mA

ANSWER: 120 mA

14) A moving iron instrument is used as an ammeter. Its range can be extended by usinga. Suitable shunt across its terminalb. A high non - inductive resistancec. Either (a) or (b)d. Neither (a) nor (b)

ANSWER: Suitable shunt across its terminal

15) For a moving iron ammeter, the change of inductance is 3 μ H / degree and its spring constant is 4X10 -7 N – m / degree. If the maximum deflection of the pointer is 90 degree, then the correspondingcurrent in the coil bea. 3.89 Ab. 4.05 Ac. 4.89 Ad. 5 A

ANSWER: 4.89 A

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16) For extending the range of 0 - 150 V to 0 - 500 V in a 10000 Ω / V meter, the value of series resistancerequired is equal toa. 3 M Ωb. 3.5 M Ωc. 4 M Ωd. 4.5 M Ω

ANSWER: 3.5 M Ω

17) A current of 2 + 3sinωt A is passed through a moving iron instrument and through a meterrespectively. The readings of the two meters area. 2 A, 2 Ab. 2 A, 2.9 Ac. 2.9 A, 2.9 Ad. 2.9 A, 2 A

ANSWER: 2.9 A, 2 A

18) In a permanent magnet moving coil instrument, the deflecting torque is a. Directly proportional to both number of turns and flux densityb. Directly proportional to the number of turns and inversely proportional to the flux densityc. Inversely proportional to the number of turns and directly proportional to the flux densityd. Inversely proportional to both number of turns and flux density

ANSWER: Directly proportional to both number of turns and flux density

19) The accuracy in a bridge measurement depends ona. Sensitivity of detectorb. Applied voltagec. Accuracy of indicatord. Both (a) and (b)

ANSWER: Both (a) and (b)

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20) The high resistances are found ina. Insulation resistance of cables and wiresb. Resistance of shunt field winding and the multipliersc. Resistance of armature windings of electrical machined. Resistance of series field winding of a dc machine

ANSWER: Insulation resistance of cables and wires

21) A null type of bridge with DC excitation is commonly known asa. Wheatstone bridgeb. Anderson bridgec. Wien bridged. Schering bridge

ANSWER: Wheatstone bridge

22) The vibration galvanometer used as detector, it responds a. Only to the fundamental frequencyb. Only to the harmonics frequencyc. Both (a) and (b)d. Does not respond to any frequency

ANSWER: Only to the fundamental frequency

23) The AC Bridge used for the measurement of inductance is / area. Maxwell’s inductance bridgeb. Hay’s bridgec. Anderson’s bridge, Owen’s bridged. All of thesee. None of these

ANSWER: All of these

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24) Under balanced condition, the current flowing through the detector is equal toa. 1 Ab. 0 Ac. Sum of the currents flowing in the adjacent arms d. Difference between the current flowing in the adjacent arms

ANSWER: 0 A

25) The dynamometer wattmeters area. More accurate on DC supplyb. More accurate on AC supplyc. Equally accurate on both AC and DC supplyd. None of these

ANSWER: Equally accurate on both AC and DC supply

26) Due to the inductance in the pressure coil of dynamometer type wattmeter, the reading will bea. High for both leading and lagging power factorsb. Low for both leading and lagging power factorsc. High for lagging power factor and low for leading power factord. Low for lagging power factor and high for leading power factor

ANSWER: High for lagging power factor and low for leading power factor

27) What will happen if the current coil & potential coil of dynamometer type wattmeter is interchanged?a. Potential coil will get damagedb. Current coil will get damagedc. Both current coil and potential coil will get damagedd. Neither potential coil nor current coil will get damaged

ANSWER: Current coil will get damaged

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28) In some wattmeters, a small capacitor is connected in parallel with the series resistor fora. Reducing error due to inductance of the series resistorb. Obtaining non inductive voltage coil currentc. Making resultant reactance capacitived. All of thesee. None of these

ANSWER: All of these

29) An electrolytic ampere hour meter can be converted into watt - hour meter bya. Multiplying them by the voltage of the circuits in which it is usedb. Multiplying them by the current of the circuits in which it is used c. Multiplying them by the power of the circuits in which it is usedd. Cannot be converted

ANSWER: Multiplying them by the voltage of the circuits in which it is used

30) Commutator type meters can be used fora. AC supplyb. DC supplyc. Both AC and DC supplyd. None of these

ANSWER: Both AC and DC supply

31) Which part is called as heart of CRO?a. CRTb. Sweep generatorc. Trigger circuitd. Amplifier

ANSWER: CRT

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32) The light emitted by the zinc silicate coated fluorescent screen of cathode ray tube is usually of a. Green colourb. Yellow colourc. Blue colourd. White colour

ANSWER: Green colour

33) If the bombardment of electrons ceases i.e. when the signal becomes zero then the light emitted bythe screen willa. Disappear immediatelyb. Persist for some time then it will disappear c. Will not disappear at alld. None of these

ANSWER: Persist for some time then it will disappear

34) The device which is used for making temporary measurements of flow isa. Venturib. Dull flow tubec. Orifice plated. Pitot static tube

ANSWER: Orifice plate

35) For the measurement of flow the cheapest device isa. Venturib. Dall flow tubec. Flow nozzled. Pitot static tube

ANSWER: Flow nozzle

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36) The instrument which is not suitable for the application in automatic control schemea. Rotametersb. Pitot static tubec. Rotary piston meterd. Orifice plate

ANSWER: Rotameters

37) Example for positive displacement meter isa. Variable area flow meterb. Turbine metersc. Rotary piston meterd. Venturi

ANSWER: Rotary piston meter

38) In electronic voltmeter, the range of input voltages can be extended by usinga. Functional switchb. Input attenuatorc. Rectifierd. Balanced bridge dc amplifier

ANSWER: Input attenuator

39) The measurement range of digital voltmeter is a. ± 1V to ± 1MVb. ± 1V to ± 1kVc. ± 1kV to ± 1MVd. ± 100 kV to ± 100MV

ANSWER: ± 1V to ± 1MV

10/11

1) Considering cost of instruments, which is better choice, active or passive?a. Active instrumentsb. Passive instrumentsc. Cost of both active and passive instruments are approximately samed. None of these

ANSWER: Passive instruments

2) In deadweight gauge, weights are added on the top of piston until the piston reaches a datum level.The datum level is known asa. Null point, where the downward force balances the fluid pressureb. Lowest point of the containerc. Highest level of fluid in the containerd. None of these

ANSWER: Null point, where the downward force balances the fluid pressure

3) The accuracy of the deflection type instruments and of the null type instruments depends ona. Linearity, calibration of springb. Calibration of spring, linearity and calibration of weightsc. Linearity and calibration of spring, calibration of weightsd. Both depends on calibration of weight

ANSWER: Linearity and calibration of spring, calibration of weights

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4) In terms of usage, deflection type instruments area. More convenient than null type instrumentb. Less convenient than null type instrumentsc. Both are equally convenientd. None of these

ANSWER: More convenient than null type instrument

5) The output of an analogue instrument variesa. Continuously and can have an infinite number of values within its range of instrumentsb. In discrete steps and can have an infinite number of values within its range of instrumentsc. Continuously and can have an finite number of values within its range of instrumentsd. In discrete steps and can have an infinite number of values within its range of instruments

ANSWER: Continuously and can have an infinite number of values within its range of instruments

6) To read and record a measurement, the indicating type instrumentsa. Always requires human interventionb. Does not requires human interventionc. Requires human intervention only when the instrument consists of a rotating pointer moving against a scaled. Requires human intervention only when the instrument consists of a rotating scale moving against a pointer

ANSWER: Always requires human intervention

7) The electromagnetic effect is generally utilized fora. Ammetersb. Voltmetersc. Wattmeters and watt - hour metersd. All of these

ANSWER: All of these

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8) The electrostatic effect is utilized fora. Ammetersb. Voltmetersc. D.C. ampere - hour metersd. Wattmeters

ANSWER: Voltmeters

9) The instrument which can be used only with the D.C. supply isa. PMMC instrumentb. Electrodynamometer instrumentc. Hot - wire instrumentd. Split phase induction type instrument

ANSWER: PMMC instrument

10) The instrument which can be used only with the A.C. supply is / area. Induction typeb. Electrostatic typec. Electrodynamometer type d. All of these

ANSWER: Induction type

11) In a hot wire ammeter the current flowing through the resistance of 10 Ω is given byI = 3 + 2 sin 300 t AThe measured value of current will bea. 2.98 Ab. 3.31 Ac. 3.62 Ad. 4.01 A

ANSWER: 3.31 A

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12) In a hot wire instrument, readings area. Dependent on frequencyb. Dependent on waveformc. Dependent on both frequency and waveformd. Independent of both frequency and waveform

ANSWER: Independent of both frequency and waveform

13) To convert a 2 mA meter with internal resistance of 120 ohm into an ammeter of range 0 – 200 mA,the value of shunt resistance required is a. 1.121 ohmb. 1.212 ohmc. 1.312 ohmd. 1.414 ohm

ANSWER: 1.212 ohm

14) If a moving iron instrument is to be used as ammeter then the coil hasa. Fewer number of turns of thin wireb. Fewer number of turns of thick wirec. Larger number of turns of thin wired. Larger number of turns of thick wire

ANSWER: Fewer number of turns of thick wire

15) If the direction of current through the coil is upward, then the iron disc will be magnetized in such away that it isa. Pushed outwardsb. Pushed upwardsc. Pushed downwardsd. Pulled inwards

ANSWER: Pulled inwards

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Control System Objective TypeQuestions With Answer

Publisher : Faculty Notes Author : Panel Of Experts

Type the URL : http://www.kopykitab.com/product/11107

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