Electrical and Electronics Measurement & Instrumentation - Set - 7

1)   In a moving coil voltmeter, the input resistance of the meter can be increased by

a. Increasing the number of turns in the coil
b. Decreasing the number of turns in the coil
c. Using the same number of coil turns made up of high resistance material
d. Both (a) & (c)
Answer  Explanation  Related Ques

ANSWER: Both (a) & (c)

Explanation:
No explanation is available for this question!


2)   The magnitude of environment - induced variation from the specified calibration condition is quantified by

a. Sensitivity drift
b. Zero drift
c. Backlash
d. Both (a) & (b)
Answer  Explanation  Related Ques

ANSWER: Both (a) & (b)

Explanation:
No explanation is available for this question!


3)   The systematic errors of an instrument can be reduced by making

a. The sensitivity of instrument to environmental input as low as possible
b. The sensitivity of instrument to environmental input as high as possible
c. Systematic errors does not depend on the sensitivity of instrument
d. None of these
Answer  Explanation  Related Ques

ANSWER: The sensitivity of instrument to environmental input as low as possible

Explanation:
No explanation is available for this question!


4)   Suitable method for the reduction of systematic errors is / are

a. Instrument must be designed carefully
b. By introducing an equal and opposite environmental input for compensating the effect of environmental input in a measurement system
c. By adding high gain feedback to measurement system
d. All of these
Answer  Explanation  Related Ques

ANSWER: All of these

Explanation:
No explanation is available for this question!


5)   If the instrument is used in wrong manner while application, then it will results in

a. Systematic error
b. Instrument error
c. Random error
d. Environmental error
Answer  Explanation  Related Ques

ANSWER: Instrument error

Explanation:
No explanation is available for this question!


6)   The undesirable characteristics of a measuring system is / are

a. Drift
b. Dead zone
c. Non linearity
d. All of these
Answer  Explanation  Related Ques

ANSWER: All of these

Explanation:
No explanation is available for this question!


7)   Calibration of instrument is an important consideration in measurement system. The errors due to instruments being out of calibration can be rectified by

a. Increasing the frequency of recalibration
b. Increasing the temperature coefficient
c. Increasing the susceptibility of measuring instrument
d. Decreasing the frequency of recalibration
Answer  Explanation  Related Ques

ANSWER: Increasing the frequency of recalibration

Explanation:
No explanation is available for this question!


8)   Random errors in a measurement system are due to

a. Environmental changes
b. Use of uncalibrated instrument
c. Poor cabling practices
d. Unpredictable effects
Answer  Explanation  Related Ques

ANSWER: Unpredictable effects

Explanation:
No explanation is available for this question!


9)   The gravity controlled instruments has to be kept

a. Vertical
b. Horizontal
c. Inclined at 45 degree
d. Inclined at 75 degree
Answer  Explanation  Related Ques

ANSWER: Vertical

Explanation:
No explanation is available for this question!


10)   A deflection of 90 degree is produced when a current of 10 A flows through the circuit and the torque of the ammeter vary as the square of the current through it. If a current of 8 A flows through it, then the deflection obtained when the instrument is spring controlled and when the instrument is gravity controlled are

a. 39.79 degree, 57.6 degree
b. 47.55 degree, 35.67 degree
c. 57.6 degree, 39.79 degree
d. 35.67 degree, 47.55 degree
Answer  Explanation  Related Ques

ANSWER: 57.6 degree, 39.79 degree

Explanation:
No explanation is available for this question!


11)   Damping torque is the torque which acts on

a. Stationary system of the instrument
b. Moving system of the instrument only when it is stationary
c. Moving system of the instrument only when it is moving
d. Stationary system of the instrument only when the moving system is moving
Answer  Explanation  Related Ques

ANSWER: Moving system of the instrument only when it is moving

Explanation:
No explanation is available for this question!


12)   Induction type instruments are generally used as

a. Ammeter
b. Voltmeter
c. Wattmeter
d. All of these
e. None of these
Answer  Explanation  Related Ques

ANSWER: All of these

Explanation:
No explanation is available for this question!


13)   A cylindrical type with split phase winding induction ammeters employs

a. A rotating disc
b. A hollow aluminium drum
c. A single flux producing winding
d. Either (a) or (b)
Answer  Explanation  Related Ques

ANSWER: A hollow aluminium drum

Explanation:
No explanation is available for this question!


14)   In induction voltmeter, split phase windings are obtained by connecting a

a. High resistances in series with windings of both the magnets
b. High resistance in series with the winding of one magnet and an inductive coil in series with the windings of other magnet
c. An inductive coil in series with the winding of one magnet and a capacitance in series with the windings of other magnet
d. Inductive coils in series with the winding of both the magnets
Answer  Explanation  Related Ques

ANSWER: High resistance in series with the winding of one magnet and an inductive coil in series with the windings of other magnet

Explanation:
No explanation is available for this question!


15)   For reducing the errors in an induction instrument the alternating current to be measured has

a. Same frequency with which the instrument was calibrated
b. High frequency compared with which the instrument was calibrated
c. Low frequency compared with which the instrument was calibrated
d. None of these
Answer  Explanation  Related Ques

ANSWER: Same frequency with which the instrument was calibrated

Explanation:
No explanation is available for this question!


16)   The frequency errors in induction instruments can be compensated by the use of

a. Non inductive shunt in both ammeters and voltmeters
b. Non inductive shunt in case of ammeters and are generally self compensated in case of voltmeters
c. Self compensated in case of both ammeters and voltmeters
d. Self compensated in case of ammeters and non inductive shunt in case of voltmeters
Answer  Explanation  Related Ques

ANSWER: Non inductive shunt in case of ammeters and are generally self compensated in case of voltmeters

Explanation:
No explanation is available for this question!


17)   The temperature errors in induction instruments can be compensated by

a. Hunting in both ammeters and voltmeters
b. Combination of shunt and swamping resistance in both ammeters and voltmeters
c. Hunting in case of ammeters and Combination of shunt and swamping resistance in case of voltmeters
d. Combination of shunt and swamping resistance in case of ammeters and hunting in case of voltmeters
Answer  Explanation  Related Ques

ANSWER: Hunting in case of ammeters and Combination of shunt and swamping resistance in case of voltmeters

Explanation:
No explanation is available for this question!


18)   Which among the following is not true about the induction instruments?

a. It can be used for ac measurements only
b. Damping is very efficient in case of induction instruments
c. Compensation for frequency temperature is not required
d. Cost is relatively high
Answer  Explanation  Related Ques

ANSWER: Compensation for frequency temperature is not required

Explanation:
No explanation is available for this question!


19)   In a moving coil of a meter swamping resistance is added to

a. Reduce the frequency error
b. Reduce the temperature error
c. Reduce the power consumption
d. All of these
Answer  Explanation  Related Ques

ANSWER: Reduce the temperature error

Explanation:
No explanation is available for this question!


20)   Swamping resistance is a resistance made up of

a. Alloy of manganin and copper
b. Alloy of aluminium and copper
c. Alloy of nickel and cobalt
d. Alloy of manganin and aluminium
Answer  Explanation  Related Ques

ANSWER: Alloy of manganin and copper

Explanation:
No explanation is available for this question!


21)   For the measurement of low resistances, Kelvin’s double bridge has high accuracy because

a. It has two set of ratio arms which eliminates effect of resistance of connecting lead
b. It has a null indicating galvanometer
c. It has two null indicator
d. It has four sets of ratio arms which eliminates the effect of resistance of connecting lead
Answer  Explanation  Related Ques

ANSWER: It has two set of ratio arms which eliminates effect of resistance of connecting lead

Explanation:
No explanation is available for this question!


22)   For the measurement of low resistances from few ohms down to one micro ohm, which of the following instrument is not suitable?

a. Potentiometer method
b. Ammeter – voltmeter method
c. Ohmmeter
d. Kelvin double bridge method
Answer  Explanation  Related Ques

ANSWER: Ohmmeter

Explanation:
No explanation is available for this question!


23)   In a slide wire potentiometer, for a voltage source of 1.012 V the jockey is kept at 101.2 cm. If the potentiometer has 20 wires of 1 m each and the resistance of wires is 800 ohm, then the value of the working current is

a. 15 mA
b. 20 mA
c. 25 mA
d. 27 mA
Answer  Explanation  Related Ques

ANSWER: 25 mA

Explanation:
No explanation is available for this question!


24)   The Wien’s bridges is suitable for the measurement of frequency of the range of

a. Less than 100 Hz
b. 100 Hz to 100 kHz
c. 1 kHz to 100 MHz
d. More than 100 MHz
Answer  Explanation  Related Ques

ANSWER: 100 Hz to 100 kHz

Explanation:
No explanation is available for this question!


25)   For the measurement of unknown inductance in terms of known capacitance, the suitable ac bridges are

a. Maxwell and Schering bridge
b. Maxwell and Wien’s bridge
c. Maxwell and Hay’s bridge
d. Hay’s and Wien’s bridge
Answer  Explanation  Related Ques

ANSWER: Maxwell and Hay’s bridge

Explanation:
No explanation is available for this question!


26)   If a capacitor is connected across a portion of resistance of multiplier of the wattmeter then the pressure coil of the circuit becomes

a. Inductive
b. Non inductive
c. Capacitive
d. Non capacitive
Answer  Explanation  Related Ques

ANSWER: Non inductive

Explanation:
No explanation is available for this question!


27)   The two wattmeters used for the measurement of power input read 50 kW each. What will be the readings of the two wattmeters if the power factor is changed to 0.8 leading keeping the total input power same?

a. 28.35W, 71.65W
b. 31.25W, 73.71W
c. 33.33W, 73.33W
d. 38.35W, 75.5W
Answer  Explanation  Related Ques

ANSWER: 28.35W, 71.65W

Explanation:
No explanation is available for this question!


28)   Ballistic galvanometer are principally used for the measurement of

a. Current
b. Voltage
c. Power
d. Electric charges
Answer  Explanation  Related Ques

ANSWER: Electric charges

Explanation:
No explanation is available for this question!


29)   Vibration galvanometer are generally used

a. For measuring electric charges
b. As null - point detectors in ac bridges
c. As null - point detectors in dc bridges
d. For measuring power
Answer  Explanation  Related Ques

ANSWER: As null - point detectors in ac bridges

Explanation:
No explanation is available for this question!


30)   The meter of a vibrating reed frequency meter depends for its indications on the

a. Electrical resonance of thin flat steel reeds
b. Mechanical resonance of thin flat steel reeds
c. Mechanical resonance of thick flat steel reeds
d. Electrical resonance of thick flat steel reeds
Answer  Explanation  Related Ques

ANSWER: Mechanical resonance of thin flat steel reeds

Explanation:
No explanation is available for this question!


31)   The potential transformers are used to measure large voltage using

a. High range voltmeter
b. Low range voltmeter
c. High range ammeter
d. Low range ammeter
Answer  Explanation  Related Ques

ANSWER: Low range voltmeter

Explanation:
No explanation is available for this question!


32)   If an instrument transformer is used to extend the ranges of AC instrument, then its reading will depend on

a. R
b. L
c. C
d. All of these
e. None of these
Answer  Explanation  Related Ques

ANSWER: None of these

Explanation:
No explanation is available for this question!


33)   If the displacement is measured with strain gauge then the number of strain gauge normally required are

a. One
b. Two
c. Three
d. Four
Answer  Explanation  Related Ques

ANSWER: Four

Explanation:
No explanation is available for this question!


34)   A capacitive pressure sensor has a typical measurement uncertainty of

a. ± 0.2%
b. ± 0.4%
c. ± 0.1%
d. ± 0.8%
Answer  Explanation  Related Ques

ANSWER: ± 0.2%

Explanation:
No explanation is available for this question!


35)   The instruments used for the measurement of pressure is / are

a. Bellows
b. Diaphragms
c. Fiber optic pressure sensors
d. All of these
e. None of the above
Answer  Explanation  Related Ques

ANSWER: All of these

Explanation:
No explanation is available for this question!


36)   LVDT which is an instrument for the measurement of displacement, works on the principal of

a. Linear inductance
b. Non - linear inductance
c. Mutual inductance
d. Linear capacitance
Answer  Explanation  Related Ques

ANSWER: Mutual inductance

Explanation:
No explanation is available for this question!


37)   In rotary variable differential transformer, the mutual inductance between the primary and secondary coils varies

a. Linearly with the angular displacement
b. Non - linearly with the angular displacement
c. Linearly with the linear displacement
d. Non - linearly with the linear displacement
Answer  Explanation  Related Ques

ANSWER: Linearly with the angular displacement

Explanation:
No explanation is available for this question!


38)   Resolver works on the principal of mutual inductance variation. It is mainly used for the measurement of

a. Linear displacement
b. Non - linear displacement
c. Rotary motion
d. All of these
Answer  Explanation  Related Ques

ANSWER: Rotary motion

Explanation:
No explanation is available for this question!


39)   In light emitting diode, the available light emitting region is

a. Less than 2.5 mm
b. From 2.5 to 25 mm
c. Greater than 25 mm
d. Greater than 50 mm
Answer  Explanation  Related Ques

ANSWER: From 2.5 to 25 mm

Explanation:
No explanation is available for this question!


40)   In liquid crystal displays, the liquid crystal exhibits properties of

a. Liquid
b. Solids
c. Gases
d. Both (a) and (b)
Answer  Explanation  Related Ques

ANSWER: Both (a) and (b)

Explanation:
No explanation is available for this question!