# Electrical and Electronics Measurement & Instrumentation - Set - 8

1)   If the quantity to be measured remains constant during the process of taking the repeated measurements then the random errors can be eliminated by

a. Calculating the mean of the number of repeated measurements
b. Calculating the median of the number of repeated measurements
c. Calculating the sum of the numbers of repeated measurements
d. Either (a) or (b)
 Answer  Explanation  Related Ques ANSWER: Either (a) or (b) Explanation: No explanation is available for this question!

2)   The error between mean of finite data set and mean of infinite data set is known as

a. True error of the mean
b. Standard error of the mean
c. Finite error
d. Infinite error
 Answer  Explanation  Related Ques ANSWER: Standard error of the mean Explanation: No explanation is available for this question!

3)   In a measurement system,

a. A single measurement components may have both random errors and systematic errors
b. A measurement system consists of several components with each component having separate errors
c. Both the statement (a) & (b) are true
d. Neither statement (a) nor statement (b) is true
 Answer  Explanation  Related Ques ANSWER: Both the statement (a) & (b) are true Explanation: No explanation is available for this question!

4)   When a 100 V moving iron voltmeter is of accuracy class 1 - 0 is used in a circuit, it reads 50 V. Then the maximum possible percentage error in the reading is

a. 1 %
b. 2 %
c. 2.5 %
d. 3 %
 Answer  Explanation  Related Ques ANSWER: 2 % Explanation: No explanation is available for this question!

5)   If the two voltage measurements are V1 = 150 ± 2% and V2 = 100 ± 4% respectively. Then the maximum percentage error in the sum of two voltage measurements is

a. ± 2.4 %
b. ± 2.6 %
c. ± 2.8 %
d. ± 3.4 %
 Answer  Explanation  Related Ques ANSWER: ± 2.8 % Explanation: No explanation is available for this question!

6)   If the resistance in a circuit is given by 80 Ω ± 0.2% and the current flowing through it is 5A ± 0.1%, then the uncertainty in the power will be

a. ± 0.2 %
b. ± 0.4 %
c. ± 0.6 %
d. ± 0.8 %
 Answer  Explanation  Related Ques ANSWER: ± 0.4 % Explanation: No explanation is available for this question!

7)   While measuring resistance by the voltmeter - ammeter method, the maximum possible percentage error in the voltmeter and ammeter are ± 1.8% and ± 1.2% respectively. Then the maximum possible percentage error in the value of resistance will be

a. ± 3%
b. ± 4%
c. ± 4.2%
d. ± 4.8%
 Answer  Explanation  Related Ques ANSWER: ± 3% Explanation: No explanation is available for this question!

8)   In a Wheatstone bridge, the formula for finding unknown resistance (R2) is given by
R2 = ( R2 R3 ) / R1
Where, R1 = 150Ω ± 0.1%
R2 = 250Ω ± 0.1%
R3 = 300Ω ± 0.1%

a. R2 = 250Ω ± 0.1%
b. R2 = 300Ω ± 0.3%
c. R2 = 750Ω ± 0.3%
d. R2 = 500Ω ± 0.3%
 Answer  Explanation  Related Ques ANSWER: R2 = 500Ω ± 0.3% Explanation: No explanation is available for this question!

9)   If the degree of damping of an instrument should be adjusted to a value which is sufficient to enable the pointer to rise quickly to its deflected position without overshooting is called as

a. Overdamped
c. Underdamped
d. None of these

10)   Due to overdamping, the instrument will become

a. Slow
b. Lethargic
c. Fast
d. Both (a) and (b)
 Answer  Explanation  Related Ques ANSWER: Both (a) and (b) Explanation: No explanation is available for this question!

11)   Electrostatic instruments are generally used as

a. Voltmeters
b. Ammeters
c. Wattmeters
d. Watt-hour meters
 Answer  Explanation  Related Ques ANSWER: Voltmeters Explanation: No explanation is available for this question!

12)   In electrostatic voltmeters, the principle of their operation is the force of attraction between electric charges on neighboring plates between which potential difference is maintained. The attracted - disc type electrostatic instruments are used for the measurement of

a. Very low voltages
b. Low voltages
c. High voltages
d. Very high voltages
 Answer  Explanation  Related Ques ANSWER: Very high voltages Explanation: No explanation is available for this question!

13)   A Kelvin’s multicellular voltmeter has a torsion head and a coach spring for

a. Protection against accidental fraction of suspension due to vibration
c. Torsion head for zero adjustment and coach spring for Protection against accidental fraction of suspension due to vibration
d. Torsion head for Protection against accidental fraction of suspension due to vibration and coach spring for zero adjustment
 Answer  Explanation  Related Ques ANSWER: Torsion head for zero adjustment and coach spring for Protection against accidental fraction of suspension due to vibration Explanation: No explanation is available for this question!

14)   Electrostatic voltmeter instruments are suitable for

a. AC work only
b. DC work only
c. Both AC and DC work
d. None of these
 Answer  Explanation  Related Ques ANSWER: Both AC and DC work Explanation: No explanation is available for this question!

15)   If an electrostatic voltmeter is used on AC circuit and has non uniform waves, then it will read

a. Average values
b. RMS values
c. Peak values
d. All of these
 Answer  Explanation  Related Ques ANSWER: RMS values Explanation: No explanation is available for this question!

16)   In electrostatic instruments iron is not used for construction. These instruments are

a. Free from hysteresis and eddy current losses
b. Free from temperature errors
c. Dependent on temperature errors
d. Both (a) and (b)
e. None of the above
 Answer  Explanation  Related Ques ANSWER: Both (a) and (b) Explanation: No explanation is available for this question!

17)   The multiplying factor of electrostatic voltmeters is given by

a. ( C + C v ) / C
b. ( C + C v ) / C v
c. C / ( C + C v )
d. C v / ( C + C v )
 Answer  Explanation  Related Ques ANSWER: ( C + C v ) / C Explanation: No explanation is available for this question!

18)   The range of electrostatic voltmeter can be extended by using

a. Resistance potential divider method
b. Capacitance potential divider method
c. Both (a) and (b)
d. None of these
 Answer  Explanation  Related Ques ANSWER: Both (a) and (b) Explanation: No explanation is available for this question!

19)   The resistance potential divider method and capacitance potential divider method is used for

a. Both AC and DC
b. Former method can be used for both AC and DC and the later method can be used only for AC
c. Former method can be used for AC only and the later method can be used for both AC and DC
d. Former method can be used for DC only and the later method can be used only for AC
 Answer  Explanation  Related Ques ANSWER: Former method can be used for both AC and DC and the later method can be used only for AC Explanation: No explanation is available for this question!

20)   The indicating instruments with linear scale is

a. PMMC
b. Electrostatic instrument
c. Dynamometer instrument
d. Thermocouple instrument
 Answer  Explanation  Related Ques ANSWER: PMMC Explanation: No explanation is available for this question!

21)   Shielding of the capacitor is done to

a. Make the value of capacitor definite
b. Balance the bridge without any problem
c. Both (a) and (b)
d. None of these
 Answer  Explanation  Related Ques ANSWER: Both (a) and (b) Explanation: No explanation is available for this question!

22)   In AC bridges, the Wagner earth devices are used to

a. Remove all the earth capacitances from the bridge circuit
b. Remove harmonics
c. Reduce error caused by stray electric field
d. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

23)   At 2 MHz, the resonance is obtained with a resonating capacitance value of 12 pF and at 400 kHz, the resonance is obtained with resonating capacitance value of 320 pF. Then the self capacitance of the coil is

a. 0.62 pF
b. 0.83 pF
c. 1.2 pF
d. 1.5 pF
 Answer  Explanation  Related Ques ANSWER: 0.62 pF Explanation: No explanation is available for this question!

24)   When a voltmeter - ammeter method is applied for the measurement of resistance, the voltmeter reads a value of 8.28 V and the ammeter reading is 4.14 mA. Then the value of the resistance will be

a. 2 kΩ
b. 2.0 kΩ
c. 2.00 kΩ
d. 2.000 kΩ
 Answer  Explanation  Related Ques ANSWER: 2.00 kΩ Explanation: No explanation is available for this question!

25)   Electrical equipments are generally earthed through an electrode to avoid shocks when someone touches the body of the equipment. The earth resistance is effected by

a. Depth of electrodes buried in the soil
b. Shape and material of earth electrodes
c. Specific resistance of the soil surrounding the electrode
d. All of these
e. None of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

26)   The earth resistance can be measured by

a. Fall of potential method
b. Using an earth tester
c. Ducter ohmmeter method
d. Only (a) and (b)
e. All the above
 Answer  Explanation  Related Ques ANSWER: Only (a) and (b) Explanation: No explanation is available for this question!

27)   The electrodynamic frequency meters have

a. Linear scale and their readings does not depends on voltage
b. Linear scale and their readings depends on voltage
c. Non linear scale and their readings does not depends on voltage
d. Non linear scale and their readings depends on voltage
 Answer  Explanation  Related Ques ANSWER: Linear scale and their readings does not depends on voltage Explanation: No explanation is available for this question!

28)   A moving iron frequency meter consists of

a. Two inductive circuits connected in parallel
b. One inductive and one non inductive circuit connected in parallel
c. Two non inductive circuits connected in parallel
d. One inductive and one non inductive circuit connected in series
 Answer  Explanation  Related Ques ANSWER: One inductive and one non inductive circuit connected in parallel Explanation: No explanation is available for this question!

29)   If the frequency of electrodynamic power factor meter is doubled then its reading will become

a. Twice of the original reading
b. Half of the original reading
c. Four times of the original reading
d. Remains unaffected
 Answer  Explanation  Related Ques ANSWER: Remains unaffected Explanation: No explanation is available for this question!

30)   Moving iron power factor meter are suitable for 3 phase balanced circuits. It consists of

a. One control spring
b. Two control spring
c. Three control spring
d. No control spring
 Answer  Explanation  Related Ques ANSWER: No control spring Explanation: No explanation is available for this question!

31)   The nominal ratio for a current transformer is given by

a. (rated primary winding current)/(rated secondary winding current)
b. (number of turns in the primary winding)/(number of turns in the secondary winding )
c. (number of turns in the secondary winding)/(number of turns in the primary winding )
d. (rated secondary winding current)/(rated primary winding current)
 Answer  Explanation  Related Ques ANSWER: (rated primary winding current)/(rated secondary winding current) Explanation: No explanation is available for this question!

32)   The resistances of potential transformer winding is minimized by using

a. Thick conductors and small length of turns
b. Thin conductors and small length of turns
c. Thin conductors and large length of turns
d. Thick conductors and large length of turns
 Answer  Explanation  Related Ques ANSWER: Thick conductors and small length of turns Explanation: No explanation is available for this question!

33)   Bourdon tube is used for the measurement of gauge pressure of

a. Gas
b. Liquid fluid
c. Solid
d. Only (a) and (b)
e. All the above
 Answer  Explanation  Related Ques ANSWER: Only (a) and (b) Explanation: No explanation is available for this question!

34)   Dead weight gauge is used for the measurement of pressure of

35)   The ionization gauge an instrument used for the measurement of

a. Very low pressure
b. Medium pressure
c. High pressure
d. Very high pressure
 Answer  Explanation  Related Ques ANSWER: Very low pressure Explanation: No explanation is available for this question!

36)   Capacitance sensor can measure very small displacement. It can be formed by varying

a. Separation
b. Area
c. Permittivity
d. Either (a) or (b) or (c)
 Answer  Explanation  Related Ques ANSWER: Either (a) or (b) or (c) Explanation: No explanation is available for this question!

37)   Optical sensors used for the displacement measurement works on the principal that

a. Intensity of light increases with distance
b. Intensity of light decreases with distance
c. Intensity of light remains constant with distance
d. Intensity of light increases with time
 Answer  Explanation  Related Ques ANSWER: Intensity of light decreases with distance Explanation: No explanation is available for this question!

38)   The detectors used in optical sensors is

a. Photodiodes
b. Phototransistors
c. Laser
d. Only (a) and (b)
e. All the above
 Answer  Explanation  Related Ques ANSWER: Only (a) and (b) Explanation: No explanation is available for this question!

39)   A liquid crystal display requires

a. An AC drive
b. A DC drive
c. Both AC and DC drive
d. None of these
 Answer  Explanation  Related Ques ANSWER: An AC drive Explanation: No explanation is available for this question!

40)   The full range of audibility in audio frequency oscillator is

a. 0 to 20 Hz
b. 20 Hz to 2 kHz
c. 20 Hz to 20 kHz
d. 20 Hz to 20 MHz
 Answer  Explanation  Related Ques ANSWER: 20 Hz to 20 kHz Explanation: No explanation is available for this question!