Electrical and Electronics Measurement & Instrumentation - Set - 5

1)   Can an instrument suffer both zero drift and sensitivity drift at the same time?

a. Yes
b. No
c. It depends on the supply voltage
d. None of these
Answer  Explanation  Related Ques

ANSWER: Yes

Explanation:
No explanation is available for this question!


2)   The non coincidence between loading and unloading curves is known as

a. Zero drift characteristics
b. Sensitivity drift characteristics
c. Hysteresis
d. Zero drift plus sensitivity drift characteristics
Answer  Explanation  Related Ques

ANSWER: Hysteresis

Explanation:
No explanation is available for this question!


3)   Hysteresis most commonly occurs in instruments that contains

a. Springs
b. Electrical windings formed round on iron core
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!


4)   In a measuring instrument, dead space is defined as the

a. Range of different input values over which there is no change in output values
b. Range of different output values for the same input values
c. Either (a) or (b)
d. None of these
Answer  Explanation  Related Ques

ANSWER: Range of different input values over which there is no change in output values

Explanation:
No explanation is available for this question!


5)   If an instruments exhibits hysteresis then

a. It also displays dead space
b. It will not display any dead space
c. Either (a) or (b)
d. None of these
Answer  Explanation  Related Ques

ANSWER: It also displays dead space

Explanation:
No explanation is available for this question!


6)   Backlash is commonly experienced in gear sets used to convert between translational and rotational motion. Backlash is a typical cause of

a. Hysteresis
b. Dead space
c. Zero drift
d. Sensitivity drift
Answer  Explanation  Related Ques

ANSWER: Dead space

Explanation:
No explanation is available for this question!


7)   A zero order system is the one in which output changes instantaneously as the input changes. The example of zero order system is

a. Potentiometer
b. Liquid - in - glass thermometer
c. Accelerometer
d. Transducer
Answer  Explanation  Related Ques

ANSWER: Potentiometer

Explanation:
No explanation is available for this question!


8)   If a balloon is equipped with temperature and altitude measuring instruments, then the order of the temperature measuring and altitude measuring instruments are

a. Zero order, first order
b. Both are first order instruments
c. Both are zero order instruments
d. First order, zero order
Answer  Explanation  Related Ques

ANSWER: First order, zero order

Explanation:
No explanation is available for this question!


9)   In a spring controlled type indicating instruments, if the controlling torque is equal to the deflecting torque then

a. Angle of deflection will be maximum
b. Current flowing through it will be maximum
c. Angle of deflection will be zero
d. Angle of deflection will be directly proportional to the current flowing through it
Answer  Explanation  Related Ques

ANSWER: Angle of deflection will be directly proportional to the current flowing through it

Explanation:
No explanation is available for this question!


10)   In measuring instruments, spiral springs are provided to

a. Lead current
b. Produce controlling torque
c. Produce damping torque
d. Lead current and produce controlling torque
Answer  Explanation  Related Ques

ANSWER: Lead current and produce controlling torque

Explanation:
No explanation is available for this question!


11)   Electrodynamic instruments can be used as

a. Ammeter
b. Voltmeter
c. Wattmeter
d. All of these
Answer  Explanation  Related Ques

ANSWER: All of these

Explanation:
No explanation is available for this question!


12)   The equivalent inductance of fixed coil and moving coil of electrodynamic instrument is given by

a. L1 + L2 + 2M
b. L1 + L2 - 2M
c. L1 + L2 + M
d. L1 + L2 - M
Answer  Explanation  Related Ques

ANSWER: L1 + L2 + 2M

Explanation:
No explanation is available for this question!


13)   The scale of electrodynamic instrument when it is used as ammeter and when it is used as voltmeter is

a. Uniform, uniform
b. Crowded near zero, crowded near zero
c. Cramped near zero, cramped in the middle
d. Uniform, cramped near zero
Answer  Explanation  Related Ques

ANSWER: Crowded near zero, crowded near zero

Explanation:
No explanation is available for this question!


14)   In an electrodynamic instrument, the number of control springs present is / are

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

ANSWER: Two

Explanation:
No explanation is available for this question!


15)   A electrodynamic ammeter has current flowing through it of 20 A and torsional constant of controlling spring of 10-6 N - m / degree. If the mutual inductance changes uniformly at the rate of 0.0025 μ H / degree, then its angular deflection for full scale is

a. 43.68 degree
b. 57.29 degree
c. 68.32 degree
d. 69.69 degree
Answer  Explanation  Related Ques

ANSWER: 57.29 degree

Explanation:
No explanation is available for this question!


16)   For a dynamometer wattmeter, the variation of inductance with angular position of moving system is 0.06 mH/radian and spring constant is 10 X 10-6 N -m / radian. The current flowing in the instrument is 8 A. If the full scale deflection is 76 degree, then the current required in the voltage coil at full scale in d.c. circuit is

a. 27.6 μA
b. 29.89 μA
c. 35.3 μA
d. 37.28 μA
Answer  Explanation  Related Ques

ANSWER: 27.6 μA

Explanation:
No explanation is available for this question!


17)   The deflection angle in hot wire instruments is

a. Directly proportional to the current
b. Directly proportional to the square of current
c. Inversely proportional to the current
d. Inversely proportional to the square of current
Answer  Explanation  Related Ques

ANSWER: Directly proportional to the square of current

Explanation:
No explanation is available for this question!


18)   Hot - wire 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!


19)   Wheatstone bridge is suitable for the measurement of

a. Low resistance
b. Medium resistance
c. High resistance
d. Very high resistance
Answer  Explanation  Related Ques

ANSWER: Medium resistance

Explanation:
No explanation is available for this question!


20)   The resistances of the various arms of Wheatstone bridge are P = 500 ohm, Q = 50 ohm, R = 1010 ohm and S = 100 ohm. The emf of the batter is 5 V and the current sensitivity of galvanometer is 8 mm / μ A. If the internal resistance of the galvanometer is 80 ohm then the deflection of galvanometer and the sensitivity of the bridge in terms of deflection per unit change of resistance are

a. 151.2 mm, 30.24 mm / ohm
b. 100 mm, 21.03 mm / ohm
c. 186 mm, 40.37 mm / ohm
d. 193 mm, 20.74 mm / ohm
Answer  Explanation  Related Ques

ANSWER: 151.2 mm, 30.24 mm / ohm

Explanation:
No explanation is available for this question!


21)   To produce a change of 2 mm in deflection of galvanometer, a change of 4 ohm is required in the unknown arm of a Wheatstone bridge. The sensitivity of the galvanometer is

a. 1 mm / ohm
b. 0.5 mm / ohm
c. 1.5 mm / ohm
d. 2 mm / ohm
Answer  Explanation  Related Ques

ANSWER: 0.5 mm / ohm

Explanation:
No explanation is available for this question!


22)   The dielectric loss of pure capacitor is equal to

a. 1
b. 0
c. Maximum
d. None of these
Answer  Explanation  Related Ques

ANSWER: 0

Explanation:
No explanation is available for this question!


23)   If δ is the loss angle then the dissipation factor is given by

a. sin δ
b. cos δ
c. tan δ
d. cot δ
Answer  Explanation  Related Ques

ANSWER: tan δ

Explanation:
No explanation is available for this question!


24)   The Schering bridges can be used at

a. low voltage
b. high voltage
c. medium voltage
d. both (a) and (b)
e. all the above
Answer  Explanation  Related Ques

ANSWER: both (a) and (b)

Explanation:
No explanation is available for this question!


25)   A wattmeter has a pressure coil resistance of 5K ohm and current coil resistance of 0.02 ohm. What load will give equal error with the two connections if the load current is 15 A at a voltage of 240 V and 0.8 power factor.

a. 20 A
b. 24 A
c. 28 A
d. 32 A
Answer  Explanation  Related Ques

ANSWER: 24 A

Explanation:
No explanation is available for this question!


26)   The readings of the two wattmeter used for the measurement of power input to a 3 phase induction motor are 850 W and 250 W respectively. The power factor of the motor is

a. 0.73
b. 0.76
c. 0.79
d. 0.85
Answer  Explanation  Related Ques

ANSWER: 0.73

Explanation:
No explanation is available for this question!


27)   What will be the power factor of an inductive load if the reading of the two wattmeters connected to measure input power of a 3 phase induction motor is 6: 3?

a. 0.86
b. 0.89
c. 0.91
d. 0.95
Answer  Explanation  Related Ques

ANSWER: 0.86

Explanation:
No explanation is available for this question!


28)   If the reading of one wattmeter is four times the other wattmeter while measuring the input power of 3 phase induction motor then the power factor of the load will be

a. 0.56
b. 0.69
c. 0.74
d. 0.81
Answer  Explanation  Related Ques

ANSWER: 0.69

Explanation:
No explanation is available for this question!


29)   Current transformers and potential transformers are used to increase the ranges of

a. AC ammeter and AC voltmeter respectively
b. AC ammeter and DC voltmeter respectively
c. DC ammeter and DC voltmeter respectively
d. DC ammeter and AC voltmeter respectively
Answer  Explanation  Related Ques

ANSWER: AC ammeter and AC voltmeter respectively

Explanation:
No explanation is available for this question!


30)   For the measurement of energy and power it is essential to know

a. Only the transformation ratio
b. Phase angle between the primary and secondary currents
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!


31)   Thermistor is a transducer. Its temperature coefficient is

a. Negative
b. Positive
c. Zero
d. None of these
Answer  Explanation  Related Ques

ANSWER: Negative

Explanation:
No explanation is available for this question!


32)   Strain gauge is a

a. Active device and converts mechanical displacement into a change of resistance
b. Passive device and converts electrical displacement into a change of resistance
c. Passive device and converts mechanical displacement into a change of resistance
d. Active device and converts electrical displacement into a change of resistance
Answer  Explanation  Related Ques

ANSWER: Passive device and converts mechanical displacement into a change of resistance

Explanation:
No explanation is available for this question!


33)   Constantan is used for measurement of dynamic strains. It is an alloy of

a. Constantan is used for measurement of dynamic strains. It is an alloy of
b. Nickel and molybdenum
c. Nickel and chromium
d. Copper and nickel
Answer  Explanation  Related Ques

ANSWER: Copper and nickel

Explanation:
No explanation is available for this question!


34)   The linear variable differential transformer transducer is

a. Inductive transducer
b. Non - inductive transducer
c. Capacitive transducer
d. Resistive transducer
Answer  Explanation  Related Ques

ANSWER: Inductive transducer

Explanation:
No explanation is available for this question!


35)   The transducer used for the measurements is / are

a. Resistance temperature detectors
b. Thermistors
c. Ultrasonic
d. All of these
Answer  Explanation  Related Ques

ANSWER: All of these

Explanation:
No explanation is available for this question!


36)   If the ambient temperature is doubled and pressure fluctuates, then the transmission time of radar through air is

a. Almost unaffected and remains same
b. Increases
c. Decreases
d. None of these
Answer  Explanation  Related Ques

ANSWER: Almost unaffected and remains same

Explanation:
No explanation is available for this question!


37)   In radiation methods, the detector system is located

a. At the top of the liquid filled tank
b. At the bottom of liquid filled tank
c. In middle of the liquid filled tank
d. Outside a liquid filled tank
Answer  Explanation  Related Ques

ANSWER: Outside a liquid filled tank

Explanation:
No explanation is available for this question!


38)   A vibrating level sensors consist of

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

ANSWER: Two piezoelectric oscillators

Explanation:
No explanation is available for this question!


39)   The different types of analog recorders are

a. Graphic recorders
b. Oscillographic recorders
c. Magnetic tape recorders
d. All of these
Answer  Explanation  Related Ques

ANSWER: All of these

Explanation:
No explanation is available for this question!


40)   X - Y recorder is the type of

a. Graphic recorders
b. Oscillographic recorders
c. Magnetic tape recorders
d. Digital recorders
Answer  Explanation  Related Ques

ANSWER: Graphic recorders

Explanation:
No explanation is available for this question!