MCQOPTIONS
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MCQOPTIONS
This section includes 41 Mcqs, each offering curated multiple-choice questions to sharpen your Electronic Mechanic knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Bellows transducers are used to measure: |
| A. | Velocity |
| B. | Humidity |
| C. | Pressure |
| D. | Torque |
| Answer» D. Torque | |
| 2. |
In mobile phones, when a user puts the phone to his/her ears, the screen goes off. Which is the sensor used for this? |
| A. | Motion sensor |
| B. | Proximity sensor |
| C. | Vibration sensor |
| D. | Temperature sensor |
| Answer» C. Vibration sensor | |
| 3. |
A transducer that converts measurand into the form of pulse is called the ___________ transducers. |
| A. | active |
| B. | analog |
| C. | digital |
| D. | pulse |
| Answer» D. pulse | |
| 4. |
A resistance wire strain gauge with a gauge factor of 2 is bonded to a steel structural member subjected to a stress of 100 MN/m2 The modulus of elasticity of steel is 200 GN/m2. The percentage change in the value of the gauges resistance due to the applied stress will be |
| A. | 0.7% |
| B. | 0.3% |
| C. | 0.5% |
| D. | 0.1% |
| Answer» E. | |
| 5. |
Capacitive transducers are normally used for: |
| A. | Static measurements |
| B. | Dynamic measurements |
| C. | Both static and dynamic measurements |
| D. | Transient measurements |
| Answer» C. Both static and dynamic measurements | |
| 6. |
Industrial RTDs for precise measurements are usually made from _____. |
| A. | Silver |
| B. | Platinum |
| C. | Aluminium |
| D. | Steel |
| Answer» C. Aluminium | |
| 7. |
List of different transducers are given. Identify passive transducer |
| A. | Hotwire meter |
| B. | ionization chamber |
| C. | magnetostriction gauge |
| D. | photoconductive cell |
| Answer» B. ionization chamber | |
| 8. |
A capacitance transducer can be used for the measurement of |
| A. | moisture |
| B. | thickness |
| C. | displacement |
| D. | All of the above |
| Answer» D. All of the above | |
| 9. |
Match List I with List II and select the correct answer using the code given below the lists : List IList IIA. Hot wire1. Gas flowB. LVDT2. DisplacementC. Piezoelectric3. CurrentD. Hall effect 4. Acceleration |
| A. | A - 1, B - 4, C - 2. D - 3 |
| B. | A - 3, B - 4, C - 2, D - 1 |
| C. | A - 1, B - 2, C - 4, D - 3 |
| D. | A - 3, B - 2, C - 4, D - 1 |
| Answer» D. A - 3, B - 2, C - 4, D - 1 | |
| 10. |
An LVDT is used to measure displacement. The LVDT feeds a voltmeter of 0-5 V range through a 250 gain amplifier. For a displacement of 0.5 mm, the output of LVDT is 2 mV. The sensitivity of the instrument is |
| A. | 0.1 V/mm |
| B. | 0.5 V/mm |
| C. | 1 V/mm |
| D. | 5 V/mm |
| Answer» D. 5 V/mm | |
| 11. |
A Wheatstone bridge is balanced if |
| A. | the ratio of resistors on one side of the bridge is one while the ratio of resistors on the other side is infinity |
| B. | the ratio of resistors on one side of the bridge is greater than the ratio of resistors on the other side |
| C. | the ratio of the resistor on one side of the bridge equals to the ratio of resistors on the other side |
| D. | none of the above |
| Answer» D. none of the above | |
| 12. |
For display of a sine wave in a CRO, what waveform is applied ot the horizontal plates? |
| A. | sinusoidal |
| B. | square |
| C. | saw-tooth |
| D. | none of the above |
| Answer» D. none of the above | |
| 13. |
Maxwell bridge measures an unknown inductance in terms of known |
| A. | capacitance |
| B. | resistance |
| C. | inductance |
| D. | frequency |
| Answer» B. resistance | |
| 14. |
One of the following transducers is very popular for measurement of rotational displacements |
| A. | Shaft encoder |
| B. | Differential capacitor |
| C. | LVDT |
| D. | Strain gauge |
| Answer» B. Differential capacitor | |
| 15. |
List of transducers are given below:a) Photoconductive cellb) Photovoltaic cellc) Piezoelectricd) ThermistorWhich of the above are active transducers? |
| A. | and b) |
| B. | and c) |
| C. | and d) |
| D. | a), b) and c) |
| Answer» C. and d) | |
| 16. |
Match List I with List IIList I(Diffusion profile measurement technique)List II(Characteristics)A. Capacitance - voltage1. Not suitable for diffusion studies in VLSI process when shallow junction profile are of interestB. Differential – conductance2. Needs Van dc graff generatorC. Spreading resistance3. Two – point probe arrangementD. RBS4. Concentration near the junction space – charge region at zero bias cannot be measuredChoose the correct answer from the options given below: |
| A. | A - 1, B - 2, C - 4, D - 3 |
| B. | A - 4, B - 1, C - 3, D - 2 |
| C. | A - 3, B - 4, C - 2, D - 1 |
| D. | A - 2, B - 3, C - 1, D - 4 |
| Answer» C. A - 3, B - 4, C - 2, D - 1 | |
| 17. |
Match the two lists and choose the correct answer from the code given below: List I (Quantity) List II (Transducer system) (a) Temperature (i) Cantilever (b) Force (ii) Manometer (c) Liquid level (iii) Dynamometer (d) Torque (iv) Bimetallic element Code: |
| A. | (a)-(iv), (b)-(ii), (c)-(iii), (d)-(i) |
| B. | (a)-(iv), (b)-(ii), (c)-(i), (d)-(iii) |
| C. | (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii) |
| D. | (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii) |
| Answer» D. (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii) | |
| 18. |
In orifice meter, vena contracta is a position where ______ is maximum and ______ is minimum. |
| A. | Velocity, static pressure |
| B. | Velocity, dynamic pressure |
| C. | Static pressure, dynamic pressure |
| D. | Acceleration, inertia |
| Answer» B. Velocity, dynamic pressure | |
| 19. |
_________ is a device that converts the thermal quantity into any physical quantity such as mechanical energy, pressure and electrical signals. |
| A. | Photometer |
| B. | Current meter |
| C. | Temperature transducer |
| D. | Voltameter |
| Answer» D. Voltameter | |
| 20. |
Find the odd one.Hint: Transducer |
| A. | Loudspeakers |
| B. | Microphones |
| C. | Microchips |
| D. | Radiation Sensors |
| Answer» E. | |
| 21. |
Capacitive transducers can be used for the measurement of liquid level. The principle of operation used in this case is the change of capacitance with change of |
| A. | Distance between plates |
| B. | Dielectric |
| C. | Area of plates |
| D. | Resonance |
| Answer» C. Area of plates | |
| 22. |
A material having a property of becoming polarised in response to applied mechanical stress is called ___________. |
| A. | ferroelectric |
| B. | superconducting |
| C. | piezoelectric |
| D. | optoelectronic |
| Answer» D. optoelectronic | |
| 23. |
Piezoelectric transducers are: |
| A. | Active transducers |
| B. | Passive transducers |
| C. | Secondary transducers |
| D. | Primary transducers |
| Answer» B. Passive transducers | |
| 24. |
On applying mechanical stresses, a material gets electrically polarized. It must be a: |
| A. | Superconducting material |
| B. | Piezoelectric material |
| C. | Material |
| D. | Ferroelectric material |
| Answer» C. Material | |
| 25. |
Math Function buttons perform which task in the DSO? |
| A. | Triggering of the signal |
| B. | Phase difference between two signals |
| C. | Addition, subtraction of the signals |
| D. | Stop the acquisition of the input signal |
| Answer» D. Stop the acquisition of the input signal | |
| 26. |
LVDT is a ______ transducer |
| A. | Eddy current |
| B. | Resistance |
| C. | Magnetostriction |
| D. | Inductive |
| Answer» E. | |
| 27. |
An LVDT is used for measuring ________. |
| A. | frequency |
| B. | speed |
| C. | temperature |
| D. | displacement |
| Answer» E. | |
| 28. |
In flow transducers, _______ is not used at higher frequencies whereas ______ is suitable for suspended fluids. |
| A. | Bellows, balloons |
| B. | Accelerometer, reluctance sensor |
| C. | Orifice meter, venturi tube |
| D. | Venturi tube, orifice meter |
| Answer» D. Venturi tube, orifice meter | |
| 29. |
In electromagnetic flow meters, dc magnetic field is not used because of ______ |
| A. | Frequency |
| B. | Electrolytic discharge |
| C. | Electrolytic polarization |
| D. | Current continuity |
| Answer» D. Current continuity | |
| 30. |
For the recording of very fast random signals, the most suitable instrument would be |
| A. | dual-trace |
| B. | sampling oscilloscope |
| C. | real-time spectrum analyzer |
| D. | scanning-type spectrum analyzer |
| Answer» D. scanning-type spectrum analyzer | |
| 31. |
Lissajous pattern obtained on CRO is used to determine |
| A. | Amplitude of applied signal |
| B. | Current in a circuit |
| C. | Distortion in a system |
| D. | Phase shift and frequency |
| E. | None of the above |
| Answer» E. None of the above | |
| 32. |
Match List-I with List-II:List-IList-IIa)LVDTi)Gas flowb)Dielectric gaugeii)Displacementc)Pirani gaugeiii)Liquid leveld)Piezo-electriciv)AccelerationChoose the correct option from those given below: |
| A. | a-ii; b-iii; c-i; d-iv |
| B. | a-i; b-iv; c-ii; d-iii |
| C. | a-i; b-iv; c-iii; d-ii |
| D. | a-ii; b-iii; c-iv; d-i |
| Answer» B. a-i; b-iv; c-ii; d-iii | |
| 33. |
A Hot-Wire Anemometer is used for the measurement of ______. |
| A. | Pressure of gases |
| B. | Velocity of gases |
| C. | Viscosity of gases |
| D. | Viscosity of liquids |
| Answer» C. Viscosity of gases | |
| 34. |
An appurtenance whose length generally does NOT exceed three times of its diameter is called ____. |
| A. | a non-return valve |
| B. | a diffuser |
| C. | an orifice |
| D. | a mouthpiece |
| Answer» E. | |
| 35. |
A thermocouple is used for the measurement of ______. |
| A. | pressure |
| B. | temperature |
| C. | density |
| D. | humidity |
| Answer» C. density | |
| 36. |
Multimeter typically provides measurement of the following for a sinusoidal waveform |
| A. | Peak |
| B. | rms |
| C. | Average |
| D. | Instantaneous |
| Answer» C. Average | |
| 37. |
LVDT cannot measure: |
| A. | Weight |
| B. | Pressure |
| C. | Acceleration |
| D. | Temperature |
| Answer» E. | |
| 38. |
Hall effect is used to determine:i. Carrier concentration in semiconductorsii. Conductivityiii. MobilityWhich of these is/are correct? |
| A. | Only i |
| B. | Only ii |
| C. | ii and iii |
| D. | I, ii and iii |
| Answer» E. | |
| 39. |
Calculate the gauge factor of a strain gauge, if the value of resistance is 152 Ohms, which changes by 5 ohms for 5000 microstrain. |
| A. | 5.58 |
| B. | 6.58 |
| C. | 3.68 |
| D. | 4.58 |
| Answer» C. 3.68 | |
| 40. |
A tactile sensor is: |
| A. | Humidity-sensitive |
| B. | Touch-sensitive |
| C. | Input-voltage sensitive |
| D. | Pressure-sensitive |
| Answer» C. Input-voltage sensitive | |
| 41. |
A thermostatic cut-out works on the principle of: |
| A. | Thermal expansion of fluids |
| B. | Expansion due to air pressure |
| C. | Variation of resistance with temperature |
| D. | Thermal expansion of metals |
| Answer» E. | |