prepared by nirajan pudasaini, inspector, nbsm · the household energy meter is a. indicating...

Prepared by Nirajan Pudasaini, Inspector, NBSM

1. Deflection method direct measurements are most widely used as. These are

1. most simple and least time consuming. *

2. least time consuming.

3. most simple.

4. most accurate.

2. A null type instrument as compared to a deflected type instrument has

1. a lower sensitivity.

2. a higher accuracy.

3. a faster response. *

4. all of the above.

3. The use of __________________ instruments is merely confined within laboratories as standardizing

instrument.

1. indicating.

2. absolute. *

3. recording.

4. integrating.

4. Comparison methods are used

1. when a high accuracy of measurement is required. *

2. because they are most simple.

3. because they take least time in measurement.

4. because they are expensive.

5. Systematic errors are

1. environmental errors.

2. observational errors.

3. instrument errors.

4. all of the above.*

6. The smallest change in measured variable to which instrument will respond is

1. resolution. *

2. accuracy.

3. precision.

4. sensitivity.


7. Which following are integrating instruments?

1. Ammeters.

2. Wattmeters.

3. Voltmeters.

4. Ampere hour and watt hour meters. *

8. The errors mainly caused by human mistakes are

1. gross error. *

2. instrumental error.

3. observational error.

4. systematic error.

9. Resolution of an instruments is

1. the maximum non linearity.

2. the maximum quantity it can measure.

3. the minimum quantity it can measure. *

4. ability to distinguish polarity.

10. The measured value of a resistance is 10.25 ohm, whereas its value of 10.22 ohm. What is absolute

error of the measurement?

1. 0.01 ohm.

2. 0.03 ohm. *

3. 15.36 ohm.

4. 10.26 ohm.

11. In measurement system, the function of the signal manipulating elements is to

1. to perform linear operation like addition and multiplication.

2. to perform non liner operation like clipping filtering, chopping and clamping.

3. change the magnitude of the input signal while retaining its *identity.

4. change the quantity under measurement to an analogues signal.

12. A pressure measurement instrument is calibrated between 10 bar and 260 bar. The scale span of the

instrument is

1. 10 bar.

2. 250 bar. *

3. 260 bar.


4. 270 bar.

The lower range of the instrument is 10 bar and upper measurement range of the instrument is 260

bar. So the scale span of the instrument is the difference between upper range and lower range

measurement value instrument.

13. If two meters X and Y require 40 mA and 50 mA respectively, to give full scale deflection, then

1. Y is more sensitive.

2. X is more sensitive. *

3. Both X and Y are equally sensitive.

4. It would not be possible to asses then sensitivity on the basis of the given data.

Resolution of X and Y meters are 40 mA and 50 mA respectively. So X meter is less than resolution

of Y meters.

14. Purely mechanical instrument cannot be used for dynamic measurements because they have

1. high inertia.

2. higher response time.

3. large time constant.

4. all of the above. *

Mechanical instruments are unable to response rapidly to the measurement of dynamic conditions due

to the fact that they have moving parts that are rigid, heavy and bulky and consequently have a large

mass and they take large response time. Mass presents inertia problems and hence these instrument

can not faithfully follow the rapid changes which are involved in dynamic instrument.

15. An analog ammeter is

1. a recording instrument.

2. a controlling instrument.

3. an absolute instrument.

4. an indicating instrument. *

16. In AC circuits, the connection of measuring instruments cause loading effect errors which may effect

1. only the magnitude of the quantity being measured.

2. only phase of the quantity being measured.

3. both of above.

4. magnitude, phase and waveform of the quantity being measured. *


17. A wattmeter reads 30.34 W. The absolute error in the measurement is – 2.22 W. What is the true value

of power?

1. 32.56 W . *

2. 28.12 W.

3. 25.45 W.

4. None of the above.

True value is equal to difference between measured value and absolute error.

18. A moving coil ammeter has a uniform scale with 50 division and gives a full scale reading 10 A. The

instrument can read up to (1/5)th of a scale division with a fair degree of certainty. What is the

resolution of the instrument in mA?

1. 25 mA.

2. 40 mA.*

3. 50 mA.

4. 80 mA.

19. Relative error is same as

1. absolute error.

2. ratio of error and true value.

3. true error. *

4. none of the above.

Relative error is the ratio of absolute error to the true value of the unknown quantity to be measured.

20. A 0 - 100 V voltmeter has a guaranteed accuracy of 2 % of full scale reading. The voltage measured

by the voltmeter is 75 V. The limiting error is in percentage

1. 3.33 %.

2. 2.66 %. *

3. 2 %.

4. 1 %.

The magnitude of the limiting error of the instrument = relative error × scale division = 0.02 × 100 =

2 V.

1. When an error in a dataset leads to the commission of another error this is

called:


1. false precision

2. propagation 3. spawning

4. horizontal error

5. cascading

6. breeding

2. Which of the following statements about accuracy and precision are true:

1. Conceptual accuracy means employing the correct database model

to represent a real-world feature or event 2. False precision applies only to positional accuracy

3. Measures of attribute accuracy vary depending upon the level of

measurement of the attribute

4. Cohen's Kappa is one measure of positional accuracy 3. Which of the following statements is true?

1. a precise measurement may be inaccurate

2. an accurate measurement may be imprecise 3. accuracy applies only to attribute data whereas precision applies to both

attribute and geographic data

4. high accuracy and high precision are both expensive to acquire 4. The degree to which information on a map or in a digital database matches true

or accepted values is referred to as:

1. precision and accuracy

2. precision

3. accuracy 4. data quality

5. attribute information

6. None of the above

5. The term "precision" refers to:

1. highly accurate data

2. measurements that are within (1mm

3. logical accuracy

4. the level of measurement and exactness of description in a GIS

database 5. All of the above

6. Examples of non-obvious sources of data are:

1. areal cover

2. map scale

3. numerical errors 4. format

5. density of observations

7. Propagation occurs when:


1. different scale maps are digitized

2. data quality reports are missing

3. one error leads to another 4. data cascades

5. none of the above

8. GIS solutions are best reported:

1. using calibration sensitive analysis

2. as ranges or rankings

3. with surrogate data analysis

4. with statistical confidence intervals

5. all of the above

6. 2 and 4 only 9. Modern GIS and CAD packages allow easy changes to map scales. Enlarging a

small scale map:

1. provides higher levels of observation

2. increases the density of observations

3. does not increase its accuracy or level of detail 4. allows better use of surrogate data

10. Many agencies now provide data quality reports for GIS data. A data quality

report:

1. ensures GIS solutions will be correct

2. requires sensitivity calibration

3. ensures precision and accuracy in digital data

4. provides information on how maps and data sets were compiled 5. none of the above

6. 2 and 4

MCQ Errors that occur during the measurement of the quantities are of

A. 2 types

B. 3 types

C. 4 types

D. 5 types

Answer A

MCQ The prefix naming as FEMTO has a factor of

A. 10-12

B. 1012

C. 1015


D. 10-15

Answer D

MCQ Systematic error occurred due to the poor calibration of the instrument that can be

corrected by

A. taking several readings

B. replacing instruments

C. taking mean of values

D. taking median of values

Answer B

MCQ Error that occurs due to equally affected measurements is called

A. random error

B. systematic error

C. frequent error

D. precision

Answer B

MCQ Error that occur during the measurement of the quantities are

A. random error

B. systematic error

C. frequent error

D. both a and b

Answer D Errors that occur during the measurement of the quantities are of

A. 2 types

B. 3 types

C. 4 types

D. 5 types

Answer A

MCQ The prefix naming as FEMTO has a factor of


A. 10-12

B. 1012

C. 1015

D. 10-15

Answer D

7. Which of the following voltmeters would you use for measuring voltage across 20 kΩ resistance?

A. Voltmeter having a resistance of 5 kΩ

B. Voltmeter having a sensitivity of 1 kW/V

C. Voltmeter having sensitivity of 10 kW/V

D. None of the above

Explanation:

Resistance of voltmeter should be very high as compared to 20 kΩ

A single phase energy meter has the rating 1200 resolutions/ kWh. If a 500 W electric gadget is used

for 4 hours, the energy meter will make

A. 1200 revolutions

B. 1800 revolutions

C. 2100 revolutions

D. 2400 revolutions

0.5 x 4 = 2 kWh = 2 x 1200 revolutions.

Capacitors are mostly imperfect (TRUE)

Wattmeter measures active power. True

There are 8 classes of accuracy as per BIS of instruments

In a strain measuring device using a strain gauge, the output quantity is

A. voltage

B. resistance


C. Impedance

D. either (a) or (b)

The measurement is done using an unbalanced bridge.

A digital voltmeter has a read out range from 0 to 999 counts. If the full scale reading is 9.999 V, the

resolution is

A. 1 V

B. 0.01 V

C. 1 mV

D. 1 μV

Resolution is the smallest change in the quantity being measured which will cause an observable

change in output. In this case it is 1 mV.

The household energy meter is

A. indicating instrument

B. recording instrument

C. integrating instrument

D. none of the above

It integrates energy over a period of time.

otentiometer method of dc voltage measurement is more accurate than direct measurement using a

voltmeter because

A. it loads the circuit to maximum extent

B. it loads the circuit moderately

C. it does not load the circuit at all

D. it uses centre zero galvanometer instead of Voltmeters


Since the circuit is not loaded, the accurate value of dc voltage is measured.

36. Which of the following are needed both for protection and metering?

A. Wattmeters

B. Instrument transformers

C. Energy meters

D.

Power factor meters

38. A dynamometer wattmeter is connected in ac circuit. The reading will be

A. V-A product

B. average power

C. peak power

D.

instantaneous power

The speed transducer using a drag cup rotor has the main advantage of

A. very high accuracy

B. low energy requirement

C. cheap construction

D. all of the above

A voltmeter using thermocouples measures

A. rms value

B. peak value

C. average value


D. peak to peak value

Which of the following measurements using a dc potentiometer do not require standardisation of potentiometer?

A. Measurement of unknown voltage

B. Measurement of resistance

C. Measurement of unknown current

D. Calibration of voltmeter

Answer & Explanation Answer: Option B

Explanation: Unknown resistance is compared with a standard resistance. Therefore standardisation of potentiometer is not necessary.

When p.f. is zero, active power is zero and the two redaings are equal and opposite.

D. When the two wattmeter read equal and opposite, p.f. is zero.

43. In a thermocouple temperature transducer, the output voltage is usually

measured by

A. high resistance ammeter

B. high resistance voltmeter

C. high resistance milli-voltmeter

D. none of the above

45. Induction wattmeter can be used in

A. ac circuit only

Loss of charge method is suitable for high resistances. True

Which method is suitable for the measurement of resistivity of good conductors of electricity ?

Loss of charge method.

Kelvin's double bridge method. *

Schering's bridge method.


Any of the above. Schering bridge is used to measure

capacitance. *

frequency.

resistance.

inductance.

The high torque by weight ratio in an analog indicating instrument indicates

high friction loss.

fast response. *

slow response.

none of above. When a signal 15 mV at 85 MHz is to be measure then which of the following instrument can be used?

VTVM.

CRO.

Moving iron voltmeter. *

Digital multimeter.

In CRO saw tooth voltage is applied at the

vertical deflecting plates.

horizontal deflecting plates. *

accelerating anode.

cathode. LVDT stands for

linear variable differential transformer.* The sensitivity of voltmeter using 0 to 5 mA meter movement is

50 Ω / Volt.

200 Ω / Volt. * 1/5ma

http://www.electrical4u.com/voltage-or-electric-potential-difference/


100 Ω / Volt.

500 Ω / Volt. Errors due to human mistakes are

systematic.

gross.*

Human eye is most sensitive to 5500 A

An electric current of 5 A is same as 5 C / sec

Ampere second could be the unit of charge

How many different combinations may be obtained with three resistors,

each having the resistance R ? 4

Which method can be used for absolute measurement of resistances ?

1. Wheatstone bridge method

Ohm’s law is not applicable to semi conductors

Least current will flow through

1. 25 ohm resistor

2. 10 ohm resistor

3. 18 ohm resistor

4. 5 ohm resistor. *

Three 3 ohm resistors are connected to form a triangle. What is the

resistance between any two of the corners 2 ohm

An electron of mass m kg and having a charge of e coulombs travels from

rest through a potential difference of V volts. Its kinetic energy will be

1. eV Joules

Kirchhoff’s second law is based on law of conservation of energy

Resistivity of a wire depends on material

The mass of proton is roughly how many times the mass of an electron?

1840


Power supplies are regulated to prevent the output voltage from changing

due to changes in the

1. supply load

2. line voltage

3. frequency

4. both line voltage and supply load *

If the resistance in a circuit with constant voltage increases, the current

will

1. decrease

All of the following have negative temperature coefficient EXCEPT gold

Specific resistance of a substance is measured in

1. ohm-cm

Which of the following has negative temperature coefficient ? electrolytes

A wire of resistance R has it length and cross-section both doubled. Its

resistance will become

1. R / 4.

2. R *

Which of the following material is not used as fuse material?

1. Silver

2. Carbon.*

3. Copper

4. Aluminium

Which material is expected to have least resistivity?

1. Mercury

2. Copper*

3. Zinc.


4. Lead

Variable resistors are wire wound resistors

A 100 W bulb is connected in series with a room heater of 750 W. What

will happen if the bulb is replaced by a 60W bulb?

--3. Heater output will decrease

Resistivity is usually expressed in terms of ohm/cm-cube

Low resistance can be accurately measured by

1. Wein's bridge

2. None of these

3. Wheat stone bridge

4. Kelvin bridge *

MCQ In order to increase the range of ammeter, the value of shunt resistance

Rs is

A. increased

B. decreased *

C. remain

D. both a and b

Answer B

MCQ The device used to measure the potential difference between two

points in volts is known as

A. ohmmeter

B. odometer

C. ammeter

D. voltmeter*

Answer D


MCQ A galvanometer of 50Ω gives full scale deflection with 2mA current as

to convert it into ammeter the range of 10A is connected with it then the shunt

resistance will be

A. 0.1Ω

B. 0.2Ω

C. 0.01Ω*

D. 0.02Ω

Answer C

MCQ The electric instrument used to measure current in amperes is known

as

A. Ammeter*

B. voltmeter

C. ohm meter

D. odometer

Answer A

MCQ In moving coil galvanometer the pole faces of U-shaped magnet are

made concave

A. to make the field radial*

B. to increase the field

C. to weaken field

D. both a and b

Answer A

prepared by nirajan pudasaini, inspector, nbsm · the household energy meter is a. indicating...

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