# Electrical and Electronics Measurement & Instrumentation Expected MCQ PDF 6 For VIZAG Exam 2017

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

a. Zero drift characteristics
b. Sensitivity drift characteristics
c. Hysteresis
d. Zero drift plus sensitivity drift characteristics

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

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

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

a. Hysteresis
c. Zero drift
d. Sensitivity drift

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

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

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: Angle of deflection will be directly proportional to the current flowing through it
10)   In measuring instruments, spiral springs are provided to
b. Produce controlling torque
c. Produce damping torque
d. Lead current and produce controlling torque

11)   Electrodynamic instruments can be used as
a. Ammeter
b. Voltmeter
c. Wattmeter
d. All of these

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: L1 + L2 + 2M
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: Crowded near zero, crowded near zero
14)   In an electrodynamic instrument, the number of control springs present is / are
a. Two
b. One
c. Four
d. Zero

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

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

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: Directly proportional to the square of current
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: Both AC and DC work
19)   Wheatstone bridge is suitable for the measurement of
a. Low resistance
b. Medium resistance
c. High resistance
d. Very high resistance

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: 151.2 mm, 30.24 mm / ohm
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

22)   The dielectric loss of pure capacitor is equal to
a. 1
b. 0
c. Maximum
d. None of these

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

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

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

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

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

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

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: AC ammeter and AC voltmeter respectively
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

31)   Thermistor is a transducer. Its temperature coefficient is
a. Negative
b. Positive
c. Zero
d. None of these

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

34)   The linear variable differential transformer transducer is
a. Inductive transducer
b. Non – inductive transducer
c. Capacitive transducer
d. Resistive transducer

35)   The transducer used for the measurements is / are
a. Resistance temperature detectors
b. Thermistors
c. Ultrasonic
d. All of these

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: Almost unaffected and remains same
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: Outside a liquid filled tank
38)   A vibrating level sensors consist of
a. One piezoelectric oscillators
b. Two piezoelectric oscillators
c. Three piezoelectric oscillators
d. Four piezoelectric oscillators

39)   The different types of analog recorders are
a. Graphic recorders
b. Oscillographic recorders
c. Magnetic tape recorders
d. All of these