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WorksheetsSensors Technology for Machines 2
Total questions: 50
Worksheet time: 25mins
What is the primary function of a sensor in machines?
Store data
Convert physical quantity to a measurable electrical signal
Increase speed
Add weight
Which of the following is an example of a direct measurement method?
Calculating length by using time
Weighing with a balance
Computing speed from distance and time
Estimating humidity by color
Dynamic response of a sensor means:
Power consumption
Rate at which the sensor output changes after an input change
Its size
Data storage
Which of the following ensures measurement accuracy and traceability in industrial sensors?
Frequent replacement
Calibration
Painting
Heating
A sensor that produces a digital output signal (on/off) is:
LDR
Proximity switch
Strain gauge
RTD
Which sensor can generate a signal without external power?
RTD
Piezoelectric sensor
Hall sensor
Ultrasonic sensor
Active sensors are those that:
Require external power to work
Work without any power
Only for light sensing
None of the above
Which is a passive sensor?
RTD
Thermocouple
LVDT
All of the above
Photoelectric sensors detect:
Movement
Light
Both of the above
Sound only
A proximity sensor can detect:
Only metal objects
Only liquids
Presence without contact
Only temperature
Piezoelectric sensors generate voltage when:
Perpendicular magnetic field is applied
Mechanically deformed
Heated
Dampened
The Hall effect is used for sensing:
Temperature
Magnetic fields
Light intensity
Humidity
Capacitive sensors most commonly detect:
Water flow
Humidity
Level and proximity
Weight
A strain gauge measures:
Light
Mechanical deformation (strain)
Voltage only
Speed
When two different metals are joined and heated at the junction, which effect is used for sensing temperature?
Hall effect
Seebeck effect
Piezoelectric effect
Magnetoresistive effect
Inductive proximity sensors are best suited for:
Detecting wood
Detecting metals without contact
Measuring humidity
Measuring light
Which sensor uses a change in resistance with temperature?
Piezo sensor
RTD
Proximity sensor
PA sensor
MEMS accelerometers are commonly found in:
Airbags and smartphones
Fans only
Humidity meters
Pressure cookers
Ultrasonic level sensors measure distance by:
Sending and receiving electrical pulses
Measuring echo time for sound waves
Detecting change in magnetic field
Sensing temperature
Light Dependent Resistors (LDR) are key in:
Smart city street lights
Fan speed control
Absorbing sound
Monitoring CO₂
Static electricity detectors in Indian textile mills prevent:
Product color fading
Dust pollution
Explosions and fires from static sparks
Flooding
Capacitive sensors in water tanks are popular because:
They are the cheapest
No moving parts, work well with contaminated water
Work only with rainwater
They measure weight
Hall sensors in Indian automotive ABS systems detect:
Water content
Wheel speed
Engine temperature
Ambient light
Piezoelectric accelerometers at BHEL Hyderabad are used for:
Paint quality checking
Shaft vibration monitoring in turbines
Counting products
Door automation
Which sensor operates in Indian Railways' bridge health systems?
Strain gauge
Proximity sensor
Thermocouple
LDR
Humidity sensors in Indian weather stations are typically:
Capacitive type
LDR
Piezo type
Hall effect
MQ-Series gas sensors in home kitchens primarily detect:
LPG/PNG leakage
Air flow
Water level
Solar intensity
Infrared sensors in elevators at Mumbai malls are used for:
Measuring power
Temperature measurement
Door safety (object/person detection)
Counting money
Vibration sensors in Tata Power plants help in:
Tracking the sun
Predictive maintenance on generators
Measuring humidity
Monitoring air pressure
Color sensors used in Tiruppur textile industries automate:
Yarn spinning
Dyeing quality checks
Water usage
Labour attendance
Which is an advantage of MEMS sensors in smart factories?
Large size
Low cost, miniaturization, and fast response
High humidity sensitivity
Non-electrical operation
Which sensor technology allows sub-ppm gas detection in polluted Indian cities?
Ultrasonic
Capacitance
NEMS gas sensors
Hall effect
Smartphones in India use which type of sensor for screen rotation?
Strain gauge
MEMS accelerometer
Phototransistor
LDR
MEMS gyroscope sensors are crucial in:
Solar panels
Drones for stability and navigation
Heat transfer measurements
Gas detection
A NEMS-based biosensor is particularly valued for:
Robustness
Extreme sensitivity for very low concentrations
Heavy-duty load measurements
No practical reason
Sensor time constant is:
The time for output to reach 100% after a step input
Time for output to reach 63% of new value after input change
Always long
Related only to cost
First-order sensors response is like:
Square wave
Exponential curve
Step function
Oscillation
Why is knowledge of sensor dynamic model important in precison CNC machines (like in Bharat Forge Pune)?
For colour selection
Predict lag/overshoot and minimize machining errors
To increase vibration
Only for maintenance logs
A second-order sensor's output may show:
Only a straight line
Overshoot and oscillation before stabilizing
No response
Constant error
Dynamic range of a sensor is:
Largest value it can measure
Ratio of largest to smallest measurable input
Physical size
Energy consumed
Which sensor is central to weigh-in-motion truck systems on Indian highways?
Piezoelectric strips
RTD
Ultrasonic
Hall effect
Indian smart city weather stations deploy which combination?
Pressure only
Rain, temperature, humidity, and wind sensors
Noise only
Vibration only
Agriculture drip irrigation control is automated using:
Capacitance-based soil moisture sensors
Colour sensor
Gas sensor
Hall effect
Automated bottle counting in Indian FMCG lines is done by:
Proximity (photoelectric) sensor
Pressure sensor
RTD
Vibration probe
IR photodiodes in Tata Sky and DishTV boxes receive signals from:
Capacitive tags
Remote controls
Water levels
Refrigerators
Railway axle/wheel monitoring now relies on which type of sensor?
Hall switch
MEMS vibration/acceleration sensor
Static probe
Humidity sensor
An LVDT (Linear Variable Differential Transformer) is mainly used for:
Detecting weight
Precise displacement and position measurement
Gas leak detection
Humidity
Which sensor controls home and garden lamps to switch automatically at dusk/dawn (Bengaluru, Pune)?
Piezo sensor
LDR
Hall effect
Ultrasonic
Monitoring powerline current in Indian substations is best accomplished with:
Hall effect sensor
LDR
Piezo
Soil moisture sensor
A core advantage of integrating multiple sensor types in smart manufacturing (Tata Steel, Maruti Suzuki):
Redundant signals
Real-time quality, predictive maintenance, and energy efficiency
Colorful dashboards
None of the above
