SnT

Mid-1 Syllabus: 

Unit-1: Introduction: Functional elements of an instrument, generalized performance characteristics of instruments – static characteristics, dynamic characteristics. Zero order, first order, second order instruments – step response, ramp response and impulse response. Response of general form of instruments to periodic input and to transient input 

Unit-2: Transducers for motion and dimensional measurements: Relative displacement, translation and rotational resistive potentiometers, resistance strain gauges, LVDT, Synchros, capacitance transducers, Piezo-electric transducers, electro-optical devices, nozzle – flapper transducers, digital displacement transducers, ultrasonic transducers, Gyroscopic sensors  

Unit-3(1): Transducers For Force Measurement: Bonded strain gauge transducers, Photo electric transducers, variable reluctance pickup, torque measurement dynamometers. Transducers For Flow Measurement: Hot wire and hot-film anemometers, Electromagnetic flow meters, laser Doppler velocity meter  

Mid-2 Syllabus: 

Unit-3(2): Transducers For Pressure Measurement: Manometers, elastic transducers, liquid systems, gas systems, very high pressure transducers.  

Unit-4: Transducers For Temperature Measurement: Thermal expansion methods, Thermometers (liquid in glass), pressure thermometers, Thermocouples, Materials configuration and techniques. Resistance thermometers, Thermistors, junction semiconductors, Sensors, Radiation methods, Optical pyrometers, Dynamic response of temperature sensors heat flux Sensors, Transducers for liquid level measurement, humidity, silicon and quartz sensors, fiber optic sensors. 

Unit-5: Smart sensors: Introduction – Primary Sensors – Excitation – Amplification – Filters – Converters – Compensation– Information Coding/Processing - Data Communication – Standards for Smart Sensor Interface – The Automation Sensors –Applications: Introduction – On-board Automobile Sensors (Automotive Sensors)– Home Appliance Sensors – Aerospace Sensors –– Sensors for Manufacturing –Sensors for Environmental Monitoring  

Unit-1: instrument, types of input, types of Response Sensors / Transducers

Unit-2: Motion, Dimension

Unit-3: Force, Flow, Pressure

Unit-4: Temperature, Liquid-level

Unit-5: Smart sensors: Characteristics, few Real-time Applications 

UNIT-1

1. A sensor collects _____ from external environment.

(a) Energy (b) dust (c) particles (d) transducer (e) none

2. A transducer converts one form of _______ to another form of _______.

(a) dust, particles (b) dust, Energy (c) Energy, Energy (d) transducer, power (e) none

3. __________ is the closeness of measured value to the true value.

(a) threshold (b) resolution (c)sensitivity (d) Precision

4. The minimum input required to produce an output is called ______

(a) threshold (b) resolution (c)sensitivity (d) Precision

5. Maximum reading of a measurement is called ______ output

(a) minimum scale (b) infinity scale (c) full scale (d) zero scale

6.The equation (dq_o)/dt + 6q_o = 5 q_i is a _______ order equation.

(a) zero order (b) first order (c) second order (d) no order

7. In general a transient input stays for _______ period of time.

(a) larger (b) infinite (c) zero (d) limited

8. If damping ratio is greater than 1, then the system is said to be ______

(a) under damped (b) critically damped (c) over damped (d) normally damped

9. If the system has a ouput response oscillating that slowly reaches stable state, then it is ___

(a) under damped (b) normally damped (c) critically damped (d) over damped

10. A periodic signal ________ for ______ time of intervals

(a) repeats, regular (b) does not repeat, irregular (c) repeats, unpredictable (d)does not repeat, predictable

Key:

1. a 2. c 3. d 4. a 5. c 6. b 7. d 8. c 9. d 10. a

UNIT-2

1. Example of a inverse transducer is _________.

(a) piezo-electric (b) solar cell (c) capacitive (d) none

2. A resistance potentiometer is a __________ order instrument.

(a) first (b) second (c) zero (d) none

3. In a resistance potentiometer, non-linearity _______with increase of load to potentiometer resistance.

(a) increases (b) none (c) does not change (d) decreases

4. In a strain-gauge, Gauge-factor =

(a) (ΔL/R)/(ΔL/R) (b) (ΔR/R)/(ΔL/L) (c) (ΔR/L)/(ΔL/R) (d) (ΔL/L)/(ΔR/R)

5. A LVDT core is made of __________ material.

(a) weak permeable (b) non- permeable (c) high permeable (d) high permittivity

6. Capacitive transducers are used for ________ measurements.

(a) flow (b) natural (c) static (d) dynamic

7. Rochelle salt belongs to _______ group.

(a) sea-salt (b) natural (c) synthetic (d) none

8. Piezo-electric transducers are ________ transducers.

(a) Active (b) Passive (c) Inverse (d) None

9. A single free-gyro can measure rotation about ____________

(a) one axis (b) two perpendicular axes (c) Eight parallel axes (d) Four axes

10. A free-gyro angular velocity = _______; where Tf is constant friction torque, Hs is angular momentum of spinning wheel

(a) ω_d = H_s/T_f (b) ω_d = T_f*H_s (c) ω_d = T_f/H_s (d) ω_d = √(T_f*H_s)

Key:

1. a 2. c 3. d 4. b 5. c 6. d 7. b 8. a 9. b 10. c

UNIT-3(1)

1. _______ strain gauge has no moving parts.

(a) Bonded (b) unbonded (c) both a, b (d) none

2. A photo-voltaic cell converts ________energy to _________.

(a) heat, electric (b) electric, heat (c) light, electric (d) electric, light

3. ________is the opposing force acting on a inductor by itself.

(a) Conductance (b) Resistance (c) Inductance (d) Reluctance

4. transducer used to measure torque is ______

(a) dynamometer (b) tachometer (c) LDR (d) LVDT

5.In a electro-magnetic flow meter, to measure the flow, it must be ______

(a) vacuum (b) air (c) conductive liquid (d) insulating liquid

6. Hot-wire anemometer transducer used to measure _______.

(a) pressure (b) flow (c) temperature (d) force

7. Doppler effect; Assume an observer at stationary position; an object that produces a frequency of fo approaches the observer; The frequency received by the observer _____

(a) does not change (b) decreases (c) none (d) increases

8. Disadvantage of hot-wire anemometer is ________

(a) it measures flow

(b) it measures force

(c) change in temperature of liquid causes change in resistance of hot-wire

(d) none

Key:

1. a  2. c  3. d  4. a   5. c   6. b   7. d   8. c

UNIT-3(2)

1. Manometer is used to measure ___________

(a) pressure (b) temperature (c) distance (d) density

2. In a diaphragm type of pressure transducer, when pressure is applied, the diaphragm moves ___________

(a) downward (b)to left (c) to right (d) upward

3. Bellows are elastic transducers that are used to measure ______

(a) temperature (b) pressure (c) distance (d) density

4. In a very high-pressure transducer, bellows are filled with ____________

(a) water (b) air (c) kerosene (d) bubbles

5. Bourdon tube is a _______ of ring structure

(a) wire (b) solid tube (c) spring (d) hollow tube

6. To remove air above the ________ of elastic transducer, a vent is provided at top.

(a) diaphragm (b) bourdon tube (c) bellows (d) manometer

Key: 1-a, 2-d, 3-b, 4-c, 5-d, 6-a

UNIT-4

1. Two different metals with different temperature coefficients are bonded firmly. Now when the junction temperature changes,

(a) nothing happens

(b) bends uniformly to a circular arc

(c) bends to a rectangular shape

(d) bends to a triangle

2. In case of liquid-in-glass thermometers, Auxiliary thermometer is used to _______

(a) read more temperature

(b) it is just dummy

(c) reduce errors

(d) increase visibility

3. Pressure thermometer uses the _______ and ________

(a) manometer, bimetallic thermometer

(b) bourdon tube, liquid-in-glass thermometer

(c) bellows, bimetallic thermometer

(d) diaphragm, liquid-in-glass thermometer

4. Two different metals firmly joined. When one of the junctions kept at reference, and other junction temperature varies, Voltage is produced. This device is called ___________

(a) Thermometer (b) Pyrometer (c) Thermocouple (d) Thermistor (e) none

5. In case of Thermistors with positive temperature coefficient, if temperature increases, then resistance _________

(a) increases (b) decreases (c) remains same (d) none

6. Optical pyrometer uses the following elements:

(a) filament of lamp (b) lens (c) eye-piece (d) a, b, c (e) none

7. While using temperature sensors, _____________ can produce promising compensation

(a) specific heat (b) rugged environment (c) speed response (e) dual-sensors

8. A Gardon-gage is better than Slug-type heat-flux sensor because

(i) large heat sink (ii) lesser heat sink (iii) thermocouple connected to heat-flux

(a) i, ii (b) ii, iii (c) i, iii (d) none

9. Liquid-level measurement: If the liquid level increases, the air pressure in the pipe ____ 

(a) decreases (b) equals (c) increases (d) does not effect

10. A smooth finished mirror type surface collects dew drop (condensation). This

measurement, method uses __________ to measure humidity.

(a) only LEDs

(b) only photo transistors

(c) thermometer

(d) LED and photo transistor

11. Fiber-optic based pressure measurement, uses _______ and ______

(i) optical fiber cable, light source

(ii) light is passed from one end of fiber and reaches the other end

(iii) the amount of light that passes the other end decreases, when pressure applied on the

optical fiber

(a) i, ii (b) ii, iii (c) i, iii (d) ) i, ii, iii

Key: 1-b, 2-c, 3-b, 4-c, 5-a, 6-d, 7-e, 8-c, 9-c, 10-d, 11-d

UNIT-5

1. Primary sensors are different from smart sensors. Primary sensors are:

(a) sensors +supply voltage + trigger input

(b) sensors only

(c) trigger input only

(d) supply voltage only

2. Power supply, trigger input (AC/DC) are called _________ which are given to a sensor

(a) excitation (b) amplification (c) filter (d) converter

3. When the input sensed by a sensor is very low, __________ is required.

(a) excitation (b) amplification (c) filter (d) converter

4. Interfacing an analog output of a sensor to a microprocessor requires _________

(a) excitation (b) amplification (c) filter (d) converter

5. Correction, compensation, linearization, processing. This is collectively called _____

(a) information coding/processing

(b) excitation

(c) amplification

(d) none

6. HART is used for data communication. HART =

(a) Highway Addressable Remote Trigger

(b) Host Addressable Remote Transducer

(c) Highway Addressable Range Transducer

(d) Highway Addressable Remote Transducer

7. Smart Sensor = Primary Sensor + _____________

(a) converter

(b) supply voltage

(c) automation

(d) transducer

8. Application of Sensors that are used in manufacturing industry:

(a) distance sensing

(b) pattern recognition

(c) machine vision

(d) all the options (a, b, c)

9. Application of aerospace sensors:

(a) head light control

(b) pattern recognition

(c) sensing direction of air-flow

(d) none

10. Application of Sensors that are used for Environmental monitoring are:

(a) pollution hazards

(b) environmental pollution

(c) ecological studies of air

(d) all the options (a, b, c)

(e) none

11. Application of Sensors that are used in manufacturing industry:

(a) distance sensing

(b) pattern recognition

(c) machine vision

(d) all the options (a, b, c)

(e) none

12. Application of Sensors that are used for on-board automobiles:

(a) flow-rate

(b) temperature

(c) oxygen

(d) all the options (a, b, c)

(e) none

13. To reduce noise in microchips/smart sensors, one of the best techniques is ___________

(a) cross-correlation

(b) semi-correlation

(c) interference

(d) all the options (a, b, c)

(e) none

14. Automation uses:

(a) distance sensing

(b) Bluetooth

(c) distributed control structure

(d) all the options (a, b, c)

(e) none

Key: 1-b, 2-a, 3-b, 4-d, 5-a, 6-d, 7-c, 8-d, 9-c, 10-d, 11-d, 12-d, 13-a, 14-c