# MCQ on static characteristics of Measuring Instrument

## MCQ on static characteristics of Measuring Instrument

MCQ on static characteristics of Measuring Instrument, Multiple Choice Questions on EMI, MCQ of instrumentation & measurement, Multiple Choice Questions on static characteristics of instrumentation & measurement systems, GATE Questions on static characteristics of Measuring Instrument

### Objective Type Questions

1. In measurement systems, which of the following static characteristics are desirable?

• Accuracy
• Sensitivity
• Reproducibility
• All of above

2. In measurement systems, which of the following are undesirable static characteristics :

• Sensitivity and accuracy
• Drift, static error, and dead zone
• Reproducibility and non-linearity
• Drift, static error, dead zone, and non-linearity

3. A pressure measurement instrument is calibrated between 10 bar and 250 bar. The scale spam of the instrument is :

• 10 bar
• 250 bar
• 240 bar
• 260 bar

while the scale range is,

• 10 bar
• 250 bar
• 240 bar
• 260 bar

4. The output of an instrument under particular environmental conditions is given by the relationship q0 = a + b qi, where qi = input and a and b are constants b ≠ 1. The theoretical input-output relationship is represented by a straight passing through zero. This is a case of

• zero drift only
• sensitivity drift only
• zero and sensitivity drift together
• none of the above

Answer: zero and sensitivity drift together

5. A reading is recorded as 23.90 C°. The reading has :

• three significant figures
• five significant figures
• four significant figures
• None of the above

6. The scale of a 0-500V voltmeter is divided into ten large divisions representing 50 V each and each large division is further subdivided into 10 small divisions, each representing 5 V. It is used for measurement of output voltage of a potentiometer which can be varied from 0 to 500V. It is observed that when the sliding contact is moved from its zero position, there is no perceptible movement of pointer of the voltmeter till the sliding contact reaches a position where the output voltage should be 5 V. Therefore, it can be concluded that :

• the threshold of the voltmeter is 5 V
• the resolution of the voltmeter is 5 V
• the sensitivity of the voltmeter is 5V
• None of the above

Answer: the threshold of the voltmeter is 5 V

7. In the centre zero analog ammeter having a range of – 10 A to + 10A, there is a detectable change of the pointer from its zero position on either side of the scale only if the current reaches a value of 1A. The ammeter has a :

• resolution of 1 A.
• the dead zone of 1 A.
• the dead zone of 2 A.
• sensitivity of 1 A

8. A pressure gauge is calibrated from 0-50 kN/m2. It has a uniform scale with 100 scale divisions. One-fifth of a scale division can be read with certainty. The gauge has a :

• resolution of 0.1 kN/m2
• threshold of 0.1 kN/m2
• dead zone of 0.2 kN/m2
• a resolution of 0.5 kN/m2

9. A d.c. circuit can be represented by an internal voltage source of 50 V with an output resistance of 100 kΩ. In order to achieve 99 percent accuracy for voltage measurement across its terminals, the voltage measuring device should have :

• a resistance of at least 10 MΩ
• the resistance of 100 kΩ
• a resistance of at least 10 Ω
• none of the above

Answer: a resistance of at least 10 MΩ

10. A d.c. circuit can be represented by a voltage source of 10 V in series with an output resistance of 1 kΩ. An ammeter of 50 Ω resistance is connected to the source terminals for measurement of current. The accuracy of measurement is nearly :

• – 4.8 percen
• + 4.8 percent
• 99 percent
• 95.2 percent

11. In a.c. circuits, the connection of measuring instruments causes loading errors which may affect

• only the magnitude of quantity being measured
• only the phase of the quantity being measured
• both the magnitude and phase of the quantity being measured
• magnitude, phase, and also the waveform of the quantity being measured

Answer: magnitude, phase, and also the waveform of the quantity being measured

12. The input resistance of a cathode ray oscilloscope is of the order of :

• tens of ohm
• megohms
• kilohms
• fraction of an ohm

13. A resistor, at room temperature of 290 K has a noise voltage of 2 µV for a 50 kHz bandwidth. The temperature at which the noise voltage is 20% of its value at room temperature is :

• 58 K
• 11.6 K
• 241.7 K
• None of the above

14. An amplifier has an input signal voltage of 25 µV and a noise voltage 2.5 µV. The signal to noise ratio is

• 10
• 100
• 10 db
• none of the above

15. Johnson noise is :

• caused by thermal agitation of free electrons carrying current thereby modulating the current
• the noise carried into a circuit through conductors
• the noise of an electromagnetic origin that is radiated into a circuit
• shot noise which results from random emission of electrons across a p n junction

Answer: caused by thermal agitation of free electrons carrying current thereby modulating the current

16. In a measurement system if a q1 is an across variable and its associated through variable is q2 (power based), the static impedance of the system is

• q1 x q2
• q1/q2
• q2/q1
• q12/q2

17. In a measurement system ‘force’ is an across variable. Its associated power based through variable is :

• translational displacement
• translational acceleration
• translational velocity
• rotational displacement

18. The values of static stiffness and compliance in a measurement system determine the amount of :

• power drain from a system
• current drain from a system
• energy drain from a system
• none of the above

Answer: energy drain from a system

19. A Wheatstone bridge is balanced with all the four resistances equal to 1 kΩ each. The bridge supply voltage is 100 V. The value of one of the resistances is changed to 1010 Ω. The output voltage is measured with a voltage measuring device of infinite resistance. The bridge sensitivity is :

• 10 V/Ω
• 25 mV/Ω
• 2.5 mV/Ω
• None of the above