Mechatronics Multiple Choice Questions on “Static Characteristics”.

**1. What is the relative error percentage of an observation taken by an ultrasonic sensor which predicts the distance of an object to be 2.12cm but the actual value is 2cm?**

a) 12%

b) 10%

c) 6%

d) 1%

Answer: c

Clarification: Given: Actual Value=2cm

Measured Value=2.12cm

Absolute error=Measured Value-Actual Value

Absolute error=2.12cm-2cm=>0.12cm

Relative error=(Absolute error/Actual Value)*100

Relative error=6%

**2. What is the relative accuracy ratio of an observation taken by a distance measuring sensor which predicts the distance of an object to be 7.19cm but the actual distance is 7.02cm?**

a) 13:719

b) 17:619

c) 17:702

d) 13:619

Answer: c

Clarification: Given: Actual Value=7.02cm

Measured Value=7.19cm

Absolute error=Measured Value-Actual Value

Absolute error=7.19cm-7.02cm=0.17cm

Relative accuracy=(Absolute error/Actual distance)

Relative accuracy=(0.17/7.02)=>17:702

**3. What is the mean value of a distance observation set taken by a distance measurement sensor?**

**Observations={2,2.13,2.1,1.9}**

a) 2.0325

b) 2.2

c) 2.125

d) 2

Answer: a

Clarification: Given: Observation set={2,2.13,2.1,1.9}

Mean=Sum of observations/Total number of observations

Mean=(2+2.13+2.1+1.9)/4

Mean=2.0325

**4. Static characteristic of a sensor cannot be found using calibration.**

a) True

b) False

Answer: b

Clarification: Static characteristic of a sensor can be found using calibration. Calibration refers to a comparison between a known or standard measurement to the unknown measurement taken by the tool which has to be calibrated.

**5. What is the relative accuracy ratio of an observation taken by a IR(Infrared) sensor which predicts the distance of an object to be 1.26 cm but the actual distance is 1cm?**

a) 13:409

b) 13:50

c) 17:719

d) 13:619

Answer: b

Clarification: Given: Actual Value=1cm

Measured Value=1.26cm

Absolute error=Measured Value-Actual Value

Absolute error=1.26cm-1cm=>0.26cm

Relative accuracy=(Absolute error/Actual distance)

Relative accuracy=(0.26/1)=>13:50

**6. Static characteristics of any sensor or transducer are determined by observing criteria’s that vary very slowly with time.**

a) True

b) False

Answer: a

Clarification: Static characteristics of any sensor or transducer are determined by observing criteria’s that vary very slowly with time. Dynamic characteristics of any sensor or transducer are determined by observing criteria’s that vary rapidly with time.

**7. Accuracy and precession are same for a sensor’s observation.**

a) True

b) False

Answer: b

Clarification: Accuracy and precession are not same for a sensor’s observation. Accuracy is the observation closest to the true value whereas precession is the closeness of a observation among the predefined sets of observations.

**8. Hysteresis error of any sensor has maximum difference between the observed value and actual value.**

a) True

b) False

Answer: a

Clarification: Hysteresis error of any sensor has maximum difference between the observed value and actual value. Inside the specified range of the sensor, it is the maximum deviated observation from the actual observation.

**9. What is the relative accuracy ratio of an observation taken by a IR(Infrared) sensor which predicts the distance of an object to be 4.16cm but the actual distance is 4.09cm?**

a) 7:409

b) 13:603

c) 17:719

d) 13:619

Answer: a

Clarification: Given: Actual Value=4.09cm

Measured Value=4.16cm

Absolute error=Measured Value-Actual Value

Absolute error=4.16cm-4.09cm=>0.07cm

Relative accuracy=(Absolute error/Actual distance)

Relative accuracy=(0.07/4.09)=>7:409

**10. What is the relative error percentage of an observation taken by a distance measuring sensor which predicts the distance of an object to be 2.32cm but the actual value is 2cm?**

a) 12%

b) 7.09%

c) 6%

d) 16%

Answer: d

Clarification: Given: Actual Value=2cm

Measured Value=2.32cm

Absolute error=Measured Value-Actual Value

Absolute error=2.32cm-2cm=>0.32cm

Relative error=(Absolute error/Actual Value)*100

Relative error=16%

**11. What is the average value of a distance observation set taken by a ultrasonic sensor?**

**Observations={5,5.413,5.41,4.97}**

a) 5.0325

b) 5.198

c) 5.125

d) 5.07325

Answer: b

Clarification: Given: Observation set={5,5.413,5.41,4.97}

Mean=Sum of observations/Total number of observations

Mean=(5+5.413+5.41+4.97)/4

Mean=5.198

**12. Static characteristics are related to the steady state response of an instrument.**

a) True

b) False

Answer: a

Clarification: Static characteristics are related to the steady state response of an instrument. Steady state response of sensor is the relationship between input and output when the output changes very slowly or remains constant after a span of time. And static characteristics are the characteristics that changes very slowly or remains constant.

**13. What is the mean value of a distance observation set taken by a distance measurement sensor?**

**Observations={3,3.213,3.11,2.97}**

a) 3.0325

b) 3.2

c) 3.125

d) 3.07325

Answer: d

Clarification: Given: Observation set={3,3.213,3.11,2.97}

Mean=Sum of observations/Total number of observations

Mean=(3+3.213+3.11+2.97)/4

Mean=3.07325

**14. What is the relative accuracy ratio of an observation taken by a distance measuring sensor which predicts the distance of an object to be 6.16cm but the actual distance is 6.03cm?**

a) 13:719

b) 13:603

c) 17:719

d) 13:619

Answer: b

Clarification: Given: Actual Value=6.03 cm

Measured Value=6.16 cm

Absolute error=Measured Value-Actual Value

Absolute error=6.16cm-6.03cm=>0.13cm

Relative accuracy=(Absolute error/Actual distance)

Relative accuracy=(0.13/6.03)=>13:603

**15. What is the relative error percentage of an observation taken by an infrared sensor which predicts the distance of an object to be 3.32cm but the actual value is 3.1cm?**

a) 12%

b) 7.09%

c) 6%

d) 1%

Answer: b

Clarification: Given: Actual Value=3.1cm

Measured Value=3.32cm

Absolute error=Measured Value-Actual Value

Absolute error=3.32cm-3.1cm=>0.22cm

Relative error=(Absolute error/Actual Value)*100

Relative error=7.09%