9294 + Mcqs in Electronics and Communication Engineering Page 145 McqOptions

7201.	The range of RTD using platinum is about
A.	-100 C to 700 C
B.	-200 C to 1000 C
C.	100 C to 1000 C
D.	about 500 C
Answer» B. -200 C to 1000 C

Discussion

7202.	A digital voltmeter has a 4 1/2 digit display. The 1 V range can measure voltage up to
A.	0.9999 V
B.	1.9999 V
C.	0.199 V
D.	9.999 V
Answer» D. 9.999 V

Discussion

7203.	Consider the following statements as regards induction and dynamometer wattmeters Dynamometer wattmeters can be used for dc only.Induction wattmeter has higher torque and dynamometer wattmeter.Induction wattmeter is less accurate, has more power consumption and more weight than dynamometer wattmeter. Which of the above statements are correct?
A.	1 only
B.	1 and 2 only
C.	2 and 3 only
D.	1 and 3 only
Answer» D. 1 and 3 only

Discussion

7204.	The sensitivity of electromagnetic digital flow meter can be increased by increasing
A.	circumferential width of rotor teeth
B.	radial depth of rotor teeth
C.	thickness of rotor teeth
D.	number of teeth
Answer» E.

Discussion

7205.	The increase in intensity of trace in a CRO causes a change in
A.	beam current
B.	frequency of time base
C.	gain of Y amplifier
D.	accelerating voltage
Answer» B. frequency of time base

Discussion

7206.	A diode peak reading VTVM and thermocouple meter are connected across output of an amplitude modulated circuit. In the absence of modulation both meters read 10 V. When sinusoidal AM is applied, VTVM reads 15V The reading of thermocouple meter will be
A.	10 V
B.	12.5 V
C.	14.1 V
D.	15 V
Answer» B. 12.5 V

Discussion

7207.	A Maxwell's bridge has the unknown inductance in one arm and resistance in the other three arms.
A.	True
B.	False
Answer» C.

Discussion

7208.	For a current transformer, the standard secondary rating is
A.	1 A or 5 A
B.	2.5 A
C.	10 A
D.	5 A or 10 A
Answer» B. 2.5 A

Discussion

7209.	If n measurements of a quantity are made, the arithmetic mean is
A.	<img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/230-2-1.png">
B.	<img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/230-2-2.png">
C.	<img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/230-2-3.png">
D.	none of the above
Answer» C. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/230-2-3.png">

Discussion

7210.	Assertion (A): Secondary instruments require calibration at frequent intervals.Reason (R): Secondary instruments have many errors.
A.	Both A and R are true and R is correct explanation of A
B.	Both A and R are true but R is not correct explanation of A
C.	A is true R is false
D.	A is false R is true
Answer» B. Both A and R are true but R is not correct explanation of A

Discussion

7211.	In ac bridge measurements, 'Wagner ground' means
A.	a special RC connection to eliminate stray magnetic effects
B.	a special RC connection to eliminate stray capacitance effects
C.	an unwanted and unintended ground connection
D.	a large metal plate buried in ground connected to one corner of bridge
Answer» C. an unwanted and unintended ground connection

Discussion

7212.	Which of these instruments has highest power consumption?
A.	Dynamometer
B.	Electrostatic
C.	Moving coil
D.	Hot wire
Answer» E.

Discussion

7213.	If A = 629 8 and B = 131 3, A - B with range of doubt is
A.	498 8
B.	498 4
C.	498 11
D.	498 13
Answer» D. 498 13

Discussion

7214.	A phase shifting transformer is used in conjunction with
A.	DC slide wire potentiometer
B.	Crompton potentiometer
C.	AC coordinate potentiometer
D.	Drysdale potentiometer
Answer» E.

Discussion

7215.	In a megger the controlling torque is provided by
A.	spring
B.	gravity
C.	coil
D.	eddy current
Answer» D. eddy current

Discussion

7216.	For measurement of high voltage capacitors the suitable bridge is
A.	Wien bridge
B.	modified De Sauty bridge
C.	Schering bridge
D.	either (a) or (b)
Answer» D. either (a) or (b)

Discussion

7217.	In a phase shifting transformer the currents in the two stator winding are in phase.
A.	True
B.	False
Answer» C.

Discussion

7218.	Assertion (A): A transducer needs an output measuring or display device for measuring a non electrical quantity.Reason (R): In some transducers the output voltage is too small and needs amplification before it can be measured.
A.	Both A and R are true and R is correct explanation of A
B.	Both A and R are true but R is not correct explanation of A
C.	A is true R is false
D.	A is false R is true
Answer» C. A is true R is false

Discussion

7219.	Acoustic strain gauges
A.	have good linearity of measurement
B.	do not have long term stability
C.	have a large range of measurement
D.	have an accuracy range of 0.1-1% depending on environment
Answer» E.

Discussion

7220.	The instrument used to check insulation of household wiring is
A.	megger
B.	ohmmeter
C.	multimeter
D.	high resistance voltmeter
Answer» B. ohmmeter

Discussion

7221.	A power factor meter has
A.	one current and one pressure circuit
B.	one current circuit and two pressure circuits
C.	two current circuits and two pressure circuits
D.	two current circuits and one pressure circuit
Answer» C. two current circuits and two pressure circuits

Discussion

7222.	In a semiconductor strain gauge, the ohmic electrical contacts are generally made of
A.	copper wire
B.	gold wire
C.	aluminium wire
D.	nickel wire
Answer» C. aluminium wire

Discussion

7223.	To measure dielectric loss you would use
A.	Anderson bridge
B.	Kelvin bridge
C.	Schering bridge
D.	Maxwell's bridge
Answer» D. Maxwell's bridge

Discussion

7224.	Minute cracks in metals and minute faults in welded joints can be detected using
A.	IR rays
B.	UV rays
C.	<span class="symbol">a</span>
D.	rays
E.	X-ray/ -rays
Answer» E. X-ray/ -rays

Discussion

7225.	A thermocouple instrument can be used over a very wide frequency range.
A.	True
B.	False
Answer» B. False

Discussion

7226.	A vibration galvanometer is a
A.	moving coil instrument
B.	moving iron instrument
C.	dynamometer instrument
D.	induction instrument
Answer» B. moving iron instrument

Discussion

7227.	Assertion (A): If the reading of an instrument is low, the error is large.Reason (R): The error of an instrument is certain percentage of its full scale deflection.
A.	Both A and R are true and R is correct explanation of A
B.	Both A and R are true but R is not correct explanation of A
C.	A is true R is false
D.	A is false R is true
Answer» B. Both A and R are true but R is not correct explanation of A

Discussion

7228.	Which of these instruments is dynamometers type?
A.	Wattmeter
B.	Power factor meter
C.	Frequency meter
D.	Both (a) and (b)
Answer» E.

Discussion

7229.	Watthour meter is an integrating instrument
A.	True
B.	False
Answer» B. False

Discussion

7230.	An ammeter is
A.	secondary instrument
B.	absolute instrument
C.	recording instrument
D.	integrating instrument
Answer» B. absolute instrument

Discussion

7231.	It is required to measure temperature in the range of 1300-1520 C. The most suitable thermocouple is
A.	chromel constantan
B.	iron constantan
C.	chromel aluminium
D.	platinum-rhodium
Answer» E.

Discussion

7232.	The resistance of voltmeter affects the accuracy of measurement in loss of charge method.
A.	True
B.	False
Answer» B. False

Discussion

7233.	In a hot wire instrument, the deflection is proportional to
A.	peak value of ac current
B.	average value of ac current
C.	rms value of ac current
D.	either (a) or (b)
Answer» B. average value of ac current

Discussion

7234.	A permanent magnet moving coil meter can be used as
A.	ac only
B.	dc only
C.	both ac and dc
D.	low frequency ac and dc
Answer» E.

Discussion

7235.	If temperature increases by about 50 , the resistance of thermistor changes to
A.	half of its initial value
B.	twice of its initial value
C.	eight times of its initial value
D.	one eight of its initial value
Answer» E.

Discussion

7236.	Which of the following draws minimum power from source?
A.	PMMC
B.	Electronic voltmeter
C.	Electrostatic voltmeter
D.	Moving iron voltmeter
Answer» C. Electrostatic voltmeter

Discussion

7237.	Without a spectrum analyser, it is not possible to determine
A.	carrier frequency
B.	antenna pattern
C.	pulse width
D.	spurious signal strength and its location
Answer» B. antenna pattern

Discussion

7238.	A hot wire instrument is not affected by stray magnetic fields.
A.	True
B.	False
Answer» B. False

Discussion

7239.	Assertion (A): A ballistic galvanometer is used to measure charge.Reason (R): In a flux meter, the damping is large.
A.	Both A and R are true and R is correct explanation of A
B.	Both A and R are true but R is not correct explanation of A
C.	A is true R is false
D.	A is false R is true
Answer» C. A is true R is false

Discussion

7240.	For measuring temperatures below 800 C with high accuracy, the best instrument is
A.	optical pyrometer
B.	thermistor based thermometer
C.	GaAs junction diode thermometer
D.	platinum resistance thermometer
Answer» E.

Discussion

7241.	To avoid the effect of stray magnetic fields in ac bridge we can use
A.	magnetic screening
B.	Wagner earthing device
C.	wave filter
D.	transformer
Answer» B. Wagner earthing device

Discussion

7242.	A resistance strain gauge is usually
A.	wire grid type
B.	foil type
C.	any of these
D.	none of these
Answer» D. none of these

Discussion

7243.	Panel instruments are generally mounted vertically.
A.	True
B.	False
Answer» B. False

Discussion

7244.	Assertion (A): Many instruments use eddy current damping.Reason (R): Eddy currents set up a magnetic flux which opposes the original movement which generates them.
A.	Both A and R are true and R is correct explanation of A
B.	Both A and R are true but R is not correct explanation of A
C.	A is true R is false
D.	A is false R is true
Answer» B. Both A and R are true but R is not correct explanation of A

Discussion

7245.	In bridge circuit of figure, equivalent resistance between A and B is
A.	1 &ohm;
B.	0.5 &ohm;
C.	2 &ohm;
D.	1.5 &ohm;
Answer» B. 0.5 &ohm;

Discussion

7246.	An induction wattmeter can be used for ac only.
A.	True
B.	False
Answer» B. False

Discussion

7247.	To measure a resistance of about 8 ohms we should use
A.	Kelvin's double bridge
B.	Wheatstone bridge
C.	Meggar
D.	Either (b) or (c)
Answer» C. Meggar

Discussion

7248.	The torque in induction wattmeters due to
A.	capacitive current
B.	electrostatic effect
C.	hall effect
D.	eddy currents
Answer» E.

Discussion

7249.	During testing of an energy meter, the energy recorded by meter was 0.05 kWh and correct energy was found to be 0.09 kWh. The error and correction respectively are
A.	-0.01 kWh and 0.01 kWh
B.	0.01 kWh and -0.01 kWh
C.	-0.01 kWh and 0.01 kWh
D.	0.01 kWh and 0.01 kWh
Answer» B. 0.01 kWh and -0.01 kWh

Discussion

7250.	A land line telemetry system is suitable for distance upto
A.	about 1 km only
B.	about 10 km only
C.	about 100 km only
D.	any of the above
Answer» B. about 10 km only

Discussion

Explore topic-wise MCQs in Engineering.

The range of RTD using platinum is about

A digital voltmeter has a 4 1/2 digit display. The 1 V range can measure voltage up to

The sensitivity of electromagnetic digital flow meter can be increased by increasing

The increase in intensity of trace in a CRO causes a change in

A diode peak reading VTVM and thermocouple meter are connected across output of an amplitude modulated circuit. In the absence of modulation both meters read 10 V. When sinusoidal AM is applied, VTVM reads 15V The reading of thermocouple meter will be

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Which of these instruments has highest power consumption?

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For measurement of high voltage capacitors the suitable bridge is

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To measure dielectric loss you would use

Minute cracks in metals and minute faults in welded joints can be detected using

A thermocouple instrument can be used over a very wide frequency range.

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Assertion (A): If the reading of an instrument is low, the error is large.Reason (R): The error of an instrument is certain percentage of its full scale deflection.

Which of these instruments is dynamometers type?

Watthour meter is an integrating instrument

An ammeter is

It is required to measure temperature in the range of 1300-1520 C. The most suitable thermocouple is

The resistance of voltmeter affects the accuracy of measurement in loss of charge method.

In a hot wire instrument, the deflection is proportional to

A permanent magnet moving coil meter can be used as

If temperature increases by about 50 , the resistance of thermistor changes to

Which of the following draws minimum power from source?

Without a spectrum analyser, it is not possible to determine

A hot wire instrument is not affected by stray magnetic fields.

Assertion (A): A ballistic galvanometer is used to measure charge.Reason (R): In a flux meter, the damping is large.

For measuring temperatures below 800 C with high accuracy, the best instrument is

To avoid the effect of stray magnetic fields in ac bridge we can use

A resistance strain gauge is usually

Panel instruments are generally mounted vertically.

Assertion (A): Many instruments use eddy current damping.Reason (R): Eddy currents set up a magnetic flux which opposes the original movement which generates them.

In bridge circuit of figure, equivalent resistance between A and B is

An induction wattmeter can be used for ac only.

To measure a resistance of about 8 ohms we should use

The torque in induction wattmeters due to

During testing of an energy meter, the energy recorded by meter was 0.05 kWh and correct energy was found to be 0.09 kWh. The error and correction respectively are

A land line telemetry system is suitable for distance upto