Course :- Mechatronics Code:- ME-433 UNIT -I Multiple Choice Questions 1. a. c.
In mechatronics system design process the term theoretical modeling is based on Constrcution b. Physical principles Experimental Data d. Equations
2. a. b.
A good example of stand alone mechatronics Washing Machine b. Wire craft Computer Integrated Manufacturing d. Humanoid robot
3 a. c.
A Bread Toaster is a Open loop System Follow-up system
Closed Loop System Servo mechanism system
4. a. c.
In Closed loop Control Dependent on the output Partially Dependent on the output
Independent on the output None of the above
5. a. c.
In feedback system Stability increases Sensitivity increases
Gain increases Disturbance increases
6. a. c.
Main requirements of a good control system is Sensitivity b. Oscillation Linearity d. Stability
7. a. c.
A regulator control system maintains the control variable as Constant set point b. Changing set point Both (a) and (b) d. None of the above
8. a. c.
The device which converts one energy into another is called a Transistor b. Transducer PLC d. Micro controller
9. a. c.
___________________ Electric iron box Car starter
is a closed loop system b. DC Motor d. Active vibration control system
10. A thermocouple is used with a compensation circuit because
the e.m.f. is not a linear function of temperature to amplify the small thermoelectric e.m.f.
to increase the time constant of the sensor because the cold junction is not held at 00C
Short Answer Questions (5 Marks) 1. 2. 3. 4. 5.
Define the term Mechatronics Describe the key elements of the mechatronics system Describe the role of mechatronics in industries List some mechatronics systems that you see every day Explain briefly the three elements of a control system with an example. Give applications. 6. Explain briefly the three elements of a measuring system with an example. Give applications. 7. What are important advantages of mechatronics systems. 8. A best example of a mechatronics system is the camera system. Justify the statement. 9. Describe the applications of mechatronics in the modern world. 10. List the advantages of a closed loop system. Questions (10 Marks) 1. Mechatronics is the synergistic integration of mechanical engineering with electronics and control engineering for the design and manufacture of products. Justify the statement. 2. Explain the mechatronics design process 3. What are the various stages in designing a mechatronics system- Explain 4. Define mechatronics and sketch the representation of mechatronics system ? 5. List the differences between traditional and mechatronic design.
UNIT -II Multiple Choice Questions 1. a. c.
2. a. b. 3 a.
4. a. c. 5.
Which of the following statements is correct? Sensors and actuators are both b. Sensors and transducers are both examples of transducers. examples of actuators. Actuators and transducers are both d. examples of sensors. What term describes the maximum expected error associated with a measurement or a sensor? Precision. b. Accuracy. Range d. Resolution. One of the most widely used forms of light sensor is the photodiode. Which of the following statements is correct? A photodiode is an example of a b. A photodiode can be used as either a photoconductive sensor. photoconductive or a photovoltaic sensor. A photodiode is an example of a d. photovoltaic sensor. Sensors that require no external power source to create an output is known as a(n) _________ sensor. active b. passive variable d. thermo
The smallest input needed to create a measurable change on the output is known as the sensor’s __________ accuracy b. linearity resolution d. precision
6. a. c.
Sensor output levels when the input is zero is known as the sensor’s _______. linearity b. resolution offset d. precision
A program (i) Asks that you enter number 1, then number 2, then number 3 and then number 4 (ii) Displays the sum of the four numbers Which option BEST describes the two statements (i) True (ii) True b. (i) True (ii) False (i) False (ii) True d. (i) False (ii) False
8. a. c.
A(n) _____ error occurs when the user makes a mistake in the use of the sensor. insertion b. application characteristic d. dynamic
For the operational amplifier circuit shown in the following figure
The output is Three times the sum of V1 and V2.
Three times the difference between V1 and V2.
Twice the sum of V1 and V2.
Twice the difference between V1 and V2.
10. Which of the following forms of temperature sensor produces a large change in its resistance with temperature, but is very non-linear? a. A platinum resistance thermometer b. A thermistor. c. A pn junction sensor. d. None of the above Short Answer Questions (5 Marks) 1. Explain the terms Accuracy and Precision 2. Explain the significance of the following information given in the specification of transducers: A piezoelectric accelerometer. Non- linearity: +0.5% of full range. 3. Explain the significance of the following information given in the specification of transducer: A capacitive linear displacement transducer. Non-linearity and hysteresis: +0.01% of full range 4. Explain the following terms (a) Sensitivity (b) Hysteresis (c) Stability and resolution 5. Explain the working principles of following sensors (a) Piezo electric sensor (b) Thermocouples (c) Proximity Sensor
6. Write two factors that need to be considered in selecting a sensor for a particular application. 7. Define repeatability and reproducibility in sensors 8. What is the role of control system in mechatronics system 9. What is Hall effect 10. How do you classify sensors Questions (10 Marks) 1. Explain the differences between sensor and transducer. 2. Explain the difference between the open loop and closed loop controllers 3. Explain with neat sketches the functioning of following sensors (a) Pyroelectric sensors (b) Thermodiodes 4. Explain the principle and application of proximity and light sensors 5. Identify the various elements that might be present in a control system involving a thermostatically controlled electric heater.
UNIT –III Electrical Actuators Multiple Choice Questions 1. a. c.
Rack and Pinion can be used to convert rotational motion to linear motion Yes b. No None d.
2. a. c.
Solenoids can be used to provide electrically operated actuators Yes b. No d.
3 a. c.
A _____________ motor is an step incremental motion machine Stepper b. Servo D. C. Motor d. A. C. Motor
____________ are electrically operated switches in changing current in one electrical circuit switches a current on or off in another circuit Relay b. Mosfet Triac d. Op-amp
a. c. 5. a. c.
An actuator wherein hydraulic energy is used to impart motion is called an __________ actuator Hydraulic b. Pneumatic Electric d. Mechancial
6. a. c.
Most Common type of electrical actuator is Solenoid b. Motor Relay d. Thyristor
7. a. c.
A buffer amplifier has gain of Infinity Unity
8. a. c.
The amplifier drift and spurious noise signals are not significant in a.c. amplifiers b. d.c. amplifiers Charge amplifiers d. None of these
9. a. c.
The properties of an ideal op-amp are It should have zero input impeadance It should have zero open loop gain
Zero Dependent upon the circuit parameters
It should have high input impeadance None of the above
10. The overall gain or amplification of a system of two amplifiers arranged in series is G1 × G2 G1−G2 a. b.
G 1+ G 2
G1 /G 2
Short Answer Questions (5 Marks) 1. What is an actuator ? List the various types of actuators. 2. What is an electrical actuator. 3. Explain briefly the working of following mechanical switching devices. (a) Solenoids (b) Relays 4. Explain briefly D.C. motor control by using MOSFETs 5. Explain briefly the following solid state devices which can be used to electronically switch circuits. (a) Diodes (b) Power MOSFETS 6. Explain briefly the following solid state devices which can be used to electronically switch circuits. (a) Bipolar Transistors (b) Thyristors 7. State the advantages and applications of Servo Motors. 8. Discuss briefly the electronic control of A.C. (induction) motor ?
Questions (10 Marks) 1. Describe the basic details of (a) Poppet Valve (b) Shuttle Valve (c) Pilot operated valve. 2. Explain the briefly the following motors (a) Permanent Magnet D.C. Motors (b) Stepper Motors. 3. What factors/specifications should be considered while selecting a motor for mechatronic applications 4. Give classification of an electric motor? 5. Describe back e.m.f? 6. Explain working principle of Synchronous motor 7. Describe the workings of a 3 phase AC motor? 8. Explain the working principle of various stepper motor? 9. Explain the working principle of stepper motors in half step mode? 10. Explain the working principle of AC Servomotors ?
UNIT –IV Mechanical Actuators Multiple Choice Questions or Blanks 1. a. c.
The fluid power devices that convert the energy of a pressurized fluid into mechanical energy to do work are called activators. b. actuators. accumulators. d. converters.
2. a. c.
Mechanical energy is converted into fluid power when air is compressed. b. Exhausted Absent d. extended
3 a. c.
Which of the following is not considered as an advantage of compressed air? Offers little risk of explosion b. No return line necessary Humidity may not be present d. Enables high working speed to be obtained
Which two properties of compressed air make possible smooth acceleration and reversal of direction of mechanical motions? Easy to store and very fast working b. Elastic and very fast working medium; medium; Compressible and elastic; d. Efficient and compressible.
5. a. c.
Which gas is commonly used in pneumatics? Oxygen b. Air Nitrogen d. Hydrogen
6. What is called pneumatic system? A pneumatic system is a system that uses compressed air to transmit and control energy. Pneumatic systems are used in controlling train doors, automatic production lines, mechanical Clamps etc 7. State any one advantages and disadvantages of pneumatic systems? High durability and reliability Pneumatic components are extremely durable and can not be damaged easily. Compared to electromotive components, pneumatic components are more durable and reliable. Requires fine tuning for optimum use 8. What are the use of pilot operated valve? A pilot valve is a small valve that controls a limited-flow control feed to a separate piloted valve. Typically, this valve controls a high pressure or high flow feed. Pilot valves are useful because they allow a small and easily operated feed to control a much higher pressure or higher flow feed, which would otherwise require a much larger force to operate
9. Classify actuators? 10. Electrical a. Ac and dc motors b. Stepper motors c. solenoids 11. Hydraulic a. Use hydraulic fluid to actuate motion 12. Pneumatic a. Use compressed air to actuate motion 10.
What is cam?
a projection on a rotating part in machinery, designed to make sliding contact with another part while rotating and impart reciprocal or variable motion to it.
Short Answer Questions (5 Marks) 1. What is a Mechanicalactuator ? List the various types of Mechanical actuators. 2. Explain the working of a pneumatic systems with the help of a neat sketch? 3. List down the elements of hydraulic systems and explain each briefly? 4. Compare physical components of hydraulic and pneumatic systems? 5. Explain rotary actuators with help of a sketch and compare it with linear actuator? 6. Explain Riverted gear train with its diagram? 7. Explain sliding spool valve in control process? 8. Explain various types of cam followers? 9. Discuss the importance of belt drives in mechanical actuation systems? 10. List down the elements of hydraulic systems and explain each briefly? Questions (10 Marks) 1. Describe the basic details of (a) Poppet Valve (b) Shuttle Valve (c) Pilot operated valve in a Hydraulic actuation system. 2. Explain the key elements in a hydraulic system with neat sketches. 3. Explain the key elements in a Pneumatic system with neat sketches. 4. List out any five Valve symbols and explain their working with neat sketches of a hydraulic actuation system. 5. State any four advantages and disadvantages of hydraulic systems and also compare with pneumatic system. 6. Explain with neat sketches (i) Single acting and (ii) Double acting cylinders in Pneumatic systems. 7. Classify Valves used in hydraulic systems and explain any two of them with neat Sketches. 8. What are piezo electric actuators ? Explain.