Mechanical Measurements Important Questions for R23 JNTU Students
Mechanical Measurements is a core subject in the R23 Mechanical Engineering syllabus. It teaches how engineers quantify physical parameters such as pressure, temperature, flow, force, displacement, speed, and vibration with high accuracy.
To help JNTU students, here is a unit-by-unit list of Mechanical Measurements important questions, covering both theory and numerical topics, written in a simple, student-friendly format, with high keyword density for Mechanical Measurements Important Questions.
Mechanical Measurements Important Questions for R23 JNTU Students (Unit-Wise)
UNIT 1: Basics of Measurement
Key Theory Questions
Define measurement and explain elements of a measurement system.
What are primary, secondary, and derived measurements?
Explain the difference between accuracy, precision, and resolution.
Define error. What are systematic and random errors?
Discuss calibration and its importance.
Explain sensitivity and linearity of instruments.
What is drift? Explain different types of drift.
Describe static and dynamic characteristics of instruments.
Explain standardization in measurements.
Discuss the process of data acquisition.
What is hysteresis in measuring instruments?
Explain the concept of repeatability and reproducibility.
Why is calibration curve essential?
Define threshold and responsiveness.
Explain input–output configuration in measuring instruments.
Numerical Focus Question
Calculate the correction value if standard reading is 20°C and instrument reads 23°C.
A thermometer shows readings 50, 51, and 49°C for the same input. Calculate precision index.
Find percentage error when the true value is 120 N and measured value is 114 N.
A device shows ±0.5% accuracy. For a range of 200 units, find absolute accuracy.
Given sensitivity = 0.8 units/°C, calculate output for 60°C.
UNIT 2: Displacement, Velocity & Acceleration Measurement
Key Theory Questions
Explain the working principle of LVDT.
What are capacitive displacement sensors?
Describe optical encoders and their applications.
Explain tachometers used for speed measurement.
Compare mechanical, electrical, and electronic tachometers.
What is a piezoelectric accelerometer?
Explain strain-gauge based displacement measurement.
Discuss velocity measurement using Doppler principle.
What is stroboscope? Explain its use.
Describe seismic instruments.
Explain rotary potentiometers.
What are inductive transducers?
Define bandwidth in dynamic measurement devices.
Explain calibration of LVDT.
Discuss non-contact vibration measurement techniques.
Numerical Focus Question
For an LVDT with sensitivity 2 mV/mm, calculate output for 8 mm displacement.
A tachometer reads 3000 rpm while actual speed is 3150 rpm. Find percentage error.
An accelerometer generates 40 mV output for 20 m/s² acceleration. Calculate sensitivity.
A potentiometer with range 0–10 V corresponds to 0–100 mm displacement. Find reading for 65 mm.
A rotor measured with a stroboscope flashes at 50 Hz. Determine rotational speed (rpm).
UNIT 3: Pressure, Temperature & Flow
Key Theory Questions
Explain Bourdon tube pressure gauge.
Discuss diaphragm and capsule pressure sensors.
What is a strain-gauge pressure transducer?
Explain thermocouples and types.
Compare RTD and thermistor.
Describe bimetallic thermometer.
What are pyrometers? Explain radiation pyrometer.
Explain variable area flow meter (rotameter).
Describe venturi meter and its applications.
Explain orifice meter construction.
Discuss anemometers for air velocity measurement.
Explain ultrasound flow measurement.
What is manometry?
Describe calorimetric flow sensors.
Explain pressure measurement using dead weight tester.
Numerical Focus Question
A U-tube manometer shows 20 cm head of water. Calculate pressure in kPa.
For a thermocouple with sensitivity 45 µV/°C, find output at 80°C.
Venturi meter: discharge coefficient = 0.98, flow rate 0.05 m³/s. Find actual flow.
Temperature error: actual = 100°C, measured = 95°C → find % error.
For RTD with R₀ = 100 Ω and α = 0.00385, find R at 50°C.
UNIT 4: Force, Torque, Power & Stress Measurement
Key Theory Questions
Explain strain gauge and gauge factor.
Describe torque measurement using prony brake.
What is load cell? Explain its working.
Compare hydraulic and pneumatic load cells.
Explain proving ring for force measurement.
How is torque measured using shaft twist?
Describe dynamometers and their types.
What is strain rosette?
Explain stress analysis using strain gauges.
Describe photo-elasticity.
Explain power measurement in rotating shafts.
What is digital load indicator?
Discuss multi-component force measurement.
Explain torsion dynamometer.
Describe torque sensor calibration.
Numerical Focus Question
Strain gauge output = 20 µε, gauge factor = 2 → find strain.
A torque of 55 Nm is applied on a shaft with 20 mm radius. Find shear stress.
A prony brake has force 50 N at 0.25 m radius. Find torque.
Shaft power: torque = 80 Nm, speed = 1200 rpm → calculate power (W).
A load cell reads 480 N for actual load 500 N. Find accuracy.
UNIT 5: Advanced Instrumentation
Key Theory Questions
Explain data acquisition system (DAQ).
What is signal conditioning?
Describe digital transducers.
Discuss telemetry and applications.
Explain frequency response of instruments.
What is aliasing in digital measurement?
Explain digital storage oscilloscope.
What are smart sensors?
Describe remote vibration monitoring.
Explain noise and interference in measurement systems.
What is FFT analyser?
Compare analog and digital signal processing.
Explain wireless sensor networks.
What is calibration of digital instruments?
Explain automation in measurement systems.
Numerical Focus Question
A DAQ has 12-bit resolution over 10 V. Find smallest detectable voltage.
Signal noise ratio = 40 dB. Find noise value for 1 V signal.
Sampling frequency = 5 kHz. Nyquist limit = ?
Digital sensor shows drift of 0.5% per year. Calculate error after 3 years.
A system has bandwidth 200 Hz. Find maximum time resolution.
Preparation Tips for Mechanical Measurements (R23)
Practice all numerical questions from error analysis, LVDT, pressure, temperature, and flow measurements.
Revise instrument characteristics thoroughly.
Draw neat diagrams for pressure gauges, thermocouples, flow meters.
Use previous JNTUH papers to observe repeating questions.
Conclusion
These Mechanical Measurements Important Questions provide complete unit-wise coverage for R23 Mechanical Engineering exams. By practicing both theory and numerical problems, students can confidently answer any question from measurement systems, sensors, transducers, and modern instrumentation methods.
