Measurement and Instrumentation Error MCQ || Measurement and Instrumentation Error Questions and Answers

11. How systematic errors are eliminated?

  1. Frequent measurement
  2. Replacement of instrument
  3. Finding mean of reading
  4. Finding variance in reading

Answer.2. Replacement of instrument

Explanation: 

Systematic errors in experimental observations usually come from the measuring instruments. They may occur because of poor calibration of the instrument or its data handling system, or because the instrument is wrongly used by the experimenter.

Systematic errors can be minimized by improving experimental techniques, selecting better instruments, and removing personal bias as far as possible.

 

12. The instruments that determine the electrical quantity to be measured directly in terms of deflection are called:

  1. Absolute instruments
  2. Integrating instruments
  3. Secondary instruments
  4. Recording instruments

Answer.3. Secondary instruments

Explanation: 

  • Secondary instruments are so constructed that the quantity being measured can only be measured by observing the output indicated by the instrument i.e. deflection of the instrument
  • These instruments are calibrated by comparison with an absolute instrument or any other secondary instrument which has already been calibrated against an absolute instrument
  • A voltmeter, a glass thermometer, and a pressure gauge are typical examples of secondary instruments

 

13. ______ are caused by the inertial properties of measuring instruments or equipment.

  1. Dynamic Error
  2. Random Error
  3. Systematic Error
  4. Gross Error

Answer.1. Dynamic Error

Explanation: 

Dynamic errors are caused by the inertial properties of measuring instruments or equipment. Consider that a varying quantity is recorded with the help of a recording device. Then the difference between the obtained function and the actual process of change of the recorded quantity in time is called the dynamic error of the given dynamic instrument. It is clear that these errors are caused by the time variation in the measured quantity.

 

14. If a zero-centered voltmeter has a scale from – 5V to +5V, then the span of it is _____.

  1. 0 V
  2. 10 V
  3. 5 V
  4. –5 V

Answer.2. 10 V

Explanation: 

The voltmeter scale is -5 V to 5 V

If voltmeter scale is -V1 to V2, then the span is given by (V2 + V1)

Now, span = 5 + 5 = 10 V

 

15. ______ error arises in the measurement due to the effect of the external conditions on the measurement.

  1. Observational Error
  2. Instrumentational Error
  3. Gross Error
  4. Environmental Error

Answer.4. Environmental Error

Explanation: 

The environmental error arises due to external conditions, which include temperature, pressure, humidity, external magnetic field, etc. We can minimize the environmental errors by maintaining the temperature and humidity of the laboratory constant through some arrangements, and ensuring that there is no external magnetic or electrostatic field around the instrument.

 

16. Repeatability and reproducibility are related to

  1. Accuracy of the instrument
  2. The precision of the instrument
  3. Both accuracy of the instrument & precision of the instrument
  4. None of these

Answer.2. The precision of the instrument

Explanation: 

Repeatability measures the variation in measurements taken by a single instrument or person under the same conditions, while reproducibility measures the degree of closeness with which a given value may be repeatedly measured. It may be specified in terms of units for a given period of time.

Repeatability and reproducibility are related to the precision of the instrument.

 

17. The type of Systematic Errors are

  1. Environmental Error
  2. Observational Error
  3. Instrumental Error
  4. All of the above

Answer.4. All of the above

Explanation: 

Systematic errors  are Divided into three parts

  • Environmental Errors
  • Observational Errors
  • Instrumental Errors

Environmental Errors: This type of error arises in the measurement due to the effect of external conditions on the measurement. The external condition includes temperature, pressure, and humidity and can also include an external magnetic field.

Observational Errors:  Observational error (or measurement error) is the difference between a measured value of a quantity and its true value. These are the errors that arise due to an individual’s bias, lack of proper setting of the apparatus, or an individual’s carelessness in taking observations. The measurement errors also include wrong readings due to Parallax errors.

Instrumental Errors: This error may arise due to imperfection or faulty adjustment of the instrument with which measurement is being taken.

 

18. The change in resistance of an electrical strain gauge with a gauge factor of 2.0 and resistance of 50 Ω when subjected to a strain of 0.001 is:

  1. 0.1 Ω
  2. 0.01 Ω
  3. 0.001 Ω
  4. 0.0001 Ω

Answer.1. 0.1 Ω

Explanation: 

Given-

GF = 2, R = 50 Ω, ε = 0.001

Now change in resistance of an electrical strain gauge can be calculated as

ΔR = 2 × 50 × 0.001

ΔR = 0.1 Ω 

 

19. _______ is an error in which an instrument gives a reading when the true reading at that time is zero.

  1. Maximum Error
  2. Negative Error
  3. Zero Error
  4. Numerical Error

Answer.3. Zero Error

Explanation: 

Zero Error is a type of error in which an instrument gives a reading when the true reading at that time is zero. For example needle of the ammeter fails to return to zero when no current flows through it.

 

20. Null type recorders are __________ recorders.

  1. Potentiometric
  2. Bridge
  3. LVDT
  4. Any of these

Answer.4. Any of these

Explanation: 

Null type instrument: An instrument in which zero or null indication determines the magnitude of the measured quantity, such type of instrument is called a null type instrument.

It uses a null detector which indicates the null condition when the measured quantity and the opposite quantity are the same.

Examples: potentiometer, bridges, LVDT etc.

Scroll to Top