QUESTION BANK III YEAR / V SEM CONTROL OF ELECTRICAL MACHINES UNIT I CONTROL CIRCUIT COMPONENTS PART - A

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1 PERIYAR CENTENARY POLYTECHNIC COLLEGE Periyar Nagar, Vallam , Thanjavur AUTONOMOUS INSTITUTION DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING QUESTION BANK III YEAR / V SEM CONTROL OF ELECTRICAL MACHINES UNIT I CONTROL CIRCUIT COMPONENTS PART - A 1. Write two types of push button switches. 2. What is selector switch? 3. Explain limit switch. 4. Write the uses of pressure switch. 5. What is float switch? 6. Write the uses of float switch. 7. Mention the types of proximity switches. 8. Write the uses of proximity switch. 9. State some relays used in control switch. 10. What is single phasing? 11. Explain ON delay timer. 12. State the advantages of solid state relay. 13. State the use of bimetallic strip. 14. Explain OFF delay timer. 15. What is relay? PART - B 1. Explain the following, (i) Limit switches, (ii) Pressure switches. 2. Explain voltage relay, dc series current relay, frequency response relay and phase failure relay. 3. Explain with circuit diagram the principle of operation of single phasing preventer. 4. Explain with neat sketch the working of dash pot overload relay. 5. Explain with a neat sketch the working of a Bimetallic Thermal over load relay.

2 6. Write notes on the following: (i) Limit switches, (ii) Electronic Timer, (iii) Solenoid type contactor. 7. Draw and explain the principle of operation of electronic timer. 8. With neat sketch explain the principle of operation of pneumatic timer. 9. Draw the control circuit of electrical and mechanical interlocking and explain briefly. 10. Explain the solenoid valve operation with neat sketch. UNIT II DC MOTOR CONTROL CIRCUITS PART - A 1. Define current limit acceleration. 2. Define definite time acceleration. 3. What is the necessity for field acceleration protection circuit? 4. Define jogging control. 5. Define the function of jogging. 6. Define inching control. 7. Explain field failure protection. 8. Write the types of electrical braking. 9. What is plugging? 10. What are the precautions to be taken for DC motor reversing control? 11. How will you reverse the direction of rotation of DC motor? PART - B 1. Briefly explain the working of series relay starter. 2. Explain with a neat diagram, the working of counter EMF starter. 3. Explain current limit acceleration starters and time limit acceleration starters. 4. Explain with a neat control circuit diagram the working of a definite time acceleration starter. 5. Draw and explain the control circuit for jogging and inching of a DC motor. 6. Explain the principle of speed control of DC motors using SCR. 7. Explain with a control circuit how dynamic braking is done in DC motor. 8. Explain with a neat control circuit diagram the speed control of DC motor using DIAC and SCR. 9. Explain with neat circuit diagram the speed control circuit using UJT and SCR. 10. Draw the control circuit for plugging of shunt motors and explain.

3 UNIT III AC MOTOR CONTROL CIRCUITS PART - A 1. Draw the current speed characteristics of an AC motor during acceleration. 2. List the factors which control the speed of a AC machine. 3. What is DOL starter? 4. Draw the control circuit for DOL starter. 5. What is star delta starter? 6. What are the types of star delta starter? 7. Mention the starter which is suitable for starting a 3HP 3 phase IM. 8. Name the starter used for slip ring induction motor. 9. Define open circuit transition. 10. What is closed circuit transition? 11. Which induction motor uses secondary frequency acceleration starters are used? 12. How will you reverse the direction of 3 phase induction motor? 13. Mention any two precautions to be taken for reversing control of AC motor. 14. Define dynamic braking in induction motors. 15. Define plugging. 16. What is plug stopping? 17. Which motor is started by using secondary frequency acceleration starter. PART - B 1. Explain with a neat control circuit the working of an Automatic star delta starter. 2. Compare semi automatic and fully automatic star delta starter. 3. Explain with neat circuit diagram the working of automatic auto transformer starter. 4. Draw the control circuit for auto transformer starter of closed circuit transition and explain. 5. Explain with a control circuit for reversing the direction of 3 phase induction motor. 6. Explain the operation with a control circuit, how dynamic breaking is done in cage induction motors. 7. Draw the control circuit for automatic rotor resistance starter for three phase slip ring induction motor and explain.

4 UNIT IV PROGRAMMABLE LOGIC CONTROLLER PART - A 1. Define PLC. 2. Mention the basic components of PLC. 3. State any two features of PLC. 4. State any two requirements of PLC. 5. State any two advantages of PLC. 6. Draw the block diagram of PLC. 7. Define input module. 8. Define output module. 9. State the interface field devices with PLC. 10. What are the methods of programming a PLC? 11. What are the additional capabilities of PLC? 12. What is program loader? 13. Draw any two symbols used for ladder logic diagram. 14. Define PLC scan. PART - B 1. Explain the different methods of programming a PLC. 2. Explain the step by step procedure to draw ladder diagram. 3. Explain the job the CPU, input/output section and memory space in a PLC. 4. Explain the working of a DOL starter using PLC ladder diagram. 5. Explain the working of a star delta starter using PLC ladder diagram. 6. Develop a ladder logic diagram for fluid filling operation. 7. Draw the schematic and wiring diagram for input module and explain. 8. Explain with neat sketches the process of input Scan, program Scan and Output Scan. UNIT V INDUSTRIAL CONTROL CIRCUITS PART - A 1. What is planner machine? 2. Explain skip hoist control. 3. State the use of skip hoist. 4. Explain the automatic control of water pump. 5. State any one of the method of heat control of oven. 6. What is the function of pressure switch in air compressor?

5 7. Name any two trouble spots in a control circuit. 8. Why conveyor system should be switched on in sequential manner? 9. What is the general procedure for trouble shooting in control circuits? 10. Under what condition in the control circuit will the air compressor motor trip? 11. What are the different operations in an elevator? PART - B 1. What is planner machine? Explain its control circuit. 2. Explain skip hoist and its control circuit? 3. Explain the circuit operation of electric oven. 4. Explain air compressor and its control circuit. 5. Explain the control circuit operation of over head crane. 6. Explain conveyor system and its control circuits. 7. Explain elevator and its control circuits.

6 PERIYAR CENTENARY POLYTECHNIC COLLEGE Periyar Nagar, Vallam , Thanjavur AUTONOMOUS INSTITUTION DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING QUESTION BANK III YEAR / V SEM MICROCONTROLLERS UNIT I ARCHITECTURE AND INSTRUCTION SET OF 8051 PART A 1. What is microcontroller? 2. How many SFRs are placed in microcontroller 8051? 3. Define DPTR 4. Mention the capacity of internal RAM and internal ROM of 8051? 5. What is the purpose of PSW register? 6. What is the purpose of SFRs? 7. Mention the three different address spaces of What are the capacities of internal data memory? 9. How many register banks are placed in internal RAM? 10. What is program counter? 11. What is the use of carry flag? 12. Where is the stack memory placed in 8051? 13. How many timer and counter are placed in 8051? 14. What is interrupt signal? 15. Name the five types of interrupt signals? 16. What is the use of PSEN signal? 17. Define clock cycle. 18. Define machine cycle. 19. How many clock cycles and states are placed in one machine cycle? 20. Define instruction cycle. PART B 1. Draw and explain the block diagram of 8051 microcontroller. 2. (a). List the special function register with their byte and bit address. (b).explain stacks and stack pointer with example. 3. Briefly explain the memory organization of 8051 microcontroller.

7 4. Explain the arithmetic instructions used in Draw the pin diagram of microcontroller 8051 and explain each pin. 6. (a).draw and explain the structure of internal RAM. (b).explain internal data memory with diagram. 7. Explain external data memory and external program memory. 8. Explain I/O ports of 8051 with diagram. 9. (a). How are the instruction used in 8051 classified? (b).explain unconditional jump instruction used in Explain bit manipulation instructions used in UNIT II PROGRAMMING EXAMPLES 1. What is assembler? PART A 2. Mention the different fields in assembly language instruction. 3. Mention two assembler directives. 4. How can you perform multiplication using 8051 microcontroller? 5. What is operand field? 6. What are the instructions used to access external RAM? 7. What are the fields used in assembly language instructions as optional? 8. What is the operation carried out when 8051 executes the instruction MOVC A,@A+DPTR? 9. Mention any two examples of direct addressing instruction. 10. Mention any four addressing modes of PART B 1. Explain the structure of assembly language. 2. Write an ALP to arrange the given set of n numbers in ascending order. 3. Write an ALP for multi byte addition. 4. Explain assembler directives. 5. Write an ALP for finding maximum value in an array. 6. Write an ALP for finding the LCM of given numbers placed in memory locations 4201H and 4202H, and store the result in memory location 4203H. 7. Explain the different modes of addressing used in Explain assembly and running of an 8051 program.

8 UNIT III I/O AND TIMER PART A 1. Mention the timers of How many bit addressable locations are placed in internal RAM of 8051? 3. Mention the operating modes of Mention the bit addresses of ports P0 and P1. 5. Mention the SFR registers used in timer operation. 6. State the use of T0 pin of State the function of M1 and M0 bits in TMOD register. 8. What is the function of C/T bit in TMOD register? 9. What is the function of TF0 bit in TCON register? 10. Find the timers clock frequency for the crystal frequency of MHz. PART-B 1. Explain the bit addresses for I/O of Explain TMOD and TCON registers. 3. Write a program to generate square wave of signal on pin P1.2 using timer 0, with minimum allowable frequency. 4. Explain counter programming. 5. Explain the steps to program the timer 1 in mode Explain bit addresses for RAM. 7. Explain in detail about the programming of 8051 timer. 8. Write a program to switch the load ON and OFF alternatively by using timer 1 in mode To write an ALP for alternatively switch ON/OFF the load connected at port pin P1.0 when the counter overflows, by using counter 1 in mode Explain the various modes of timer operation with diagram. UNIT IV PART A 1. How will you double the baud rate in 8051? 2. What is the function of SMOD in PCON register? 3. What is RS232C? 4. How many timers are in 8051? Specify their names? 5. Define timer operation. 6. How is the serial transmission initiated in 8051? 7. Define counter operation. 8. What is the use of gate bit in TMOD register? 9. What is interrupt signal? 10. Specify the priorities of interrupts within level.

9 11. Mention the various types of interrupts in What is the use of RS232? 13. Specify the baud rate of serial communication in mode What are the registers used for 8051 serial communication? 15. Why are drivers used in between RS232 and microcontroller? 16. Specify the vector addresses of 8051 timer interrupts What are the SFR registers used in interrupts operations? 18. What is the function of REN bit in SCON register? PART-B 1. Explain timer programming. 2. Explain the interrupts of Explain the function of each bit of SCON and PCON registers. 4. Explain IP and IE registers. 5. Explain counter programming. 6. Explain external interrupts. 7. Explain serial port interrupts. 8. Explain the baud rates of serial communication in Explain about the serial port programming. 10. Draw the interfacing diagram of RS232 with 8051 and explain its operation. UNIT-V PART-A 1. Define peripherals. 2. How is I/O mode of 8255 classified? 3. Mention the ports placed in What is interfacing? 5. State the modes of operation of What is relay? 7. Specify the three I/O modes of Mention the ports placed in group A and group B of What is the use of 8255? 10. Mention the three important components of electromagnetic relay. 11. Define opto isolator. 12. Define ADC. 13. What is the use of IC 8253? 14. How is the output voltage of LM34 varied? 15. Which technique is used in ADC 0808? 16. Define transducers. 17. How many counters placed in 8253? 18. What is the use of RTC? 19. What is the use of stepper motor? 20. Specify some important LCD modules Define DAC.

10 22. Which technique is used for varying the speed of dc motors used in microcontroller? 23. How is the output voltage of LM35 varied? 24. Mention the two important registers placed in LCD. 25. Mention the different types of seven segment LEDs. PART-B 1. a) With the diagram explain how 8051 is interfaced to external memory? b) With the interfacing diagram, explain the operation of relay. 2. a) Explain the various modes of operation of b) Draw the interfacing diagram of ADC 0808 with 8051 and explain its operation. 3. a) Explain the control word format for I/O modes of b) Draw the interfacing diagram of lm35 with microcontroller and explain its operation. 4. a) Draw the interfacing diagram of DAC 0808 with 8051 and explain its operation. b) Draw the interfacing diagram of LCD with 8051 and explain its operation. 5. a)with the diagram explain how is8255 interfaced with b) Draw the pin out diagram of LCD and explain each pin. 6. a) Draw the interfacing diagram of 4 digit seven segment LED display with microcontroller 8051 and explain its operation. b) Draw the pin out diagram of DS RTC and explain each pin. 7. a) Draw and explain the block diagram of b) Draw the interfacing diagram of DC motor with microcontroller 8051 and explain its operation. 8. a) Draw the interfaccing diagram of matrix keyboard with microcontroller 8051 and explain its operation. b) Draw the interfacing diagram of stepper motor with 8051 and explain its operation.

11 PERIYAR CENTENARY POLYTECHNIC COLLEGE Periyar Nagar, Vallam , Thanjavur AUTONOMOUS INSTITUTION DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING QUESTION BANK III YEAR / V SEM POWER SYSTEM I UNIT I PART - A 16. State the conventional sources of power generation. 17. State the non renewable energy sources of power generation. 18. Give two uses of load curve. 19. What is load duration curve. 20. What is inter connected system? 21. What is base load plant? Give examples. 22. What is cogeneration? 23. What is fuel cell? 24. What are the advantages of fuel cell? 25. State the applications of fuel cell. 26. State the types of fuel cell. 27. What is the efficiency of fuel cell? 28. What is stand alone system? 29. List the advantages of interconnected grid system. PART - B 11. What is load curve? Give the uses of load curve. 12. What is base load plant and peak load plant? Give two examples for each power plant. 13. What are the conventional sources of power generation? 14. Explain the selection site of nuclear power plant. 15. Draw and explain the schematic arrangement of thermal power plant. 16. Draw and explain the schematic arrangement of Hydral power plant. 17. Draw and explain the schematic arrangement of diesel power plant. 18. Draw and explain the schematic arrangement of Nuclear power plant.

12 19. Explain with neat sketch the various parts of a nuclear reactor. 20. Draw and explain the schematic arrangement of gas power plant. 21. Explain the pumped storage power scheme. 22. Compare the Thermal, Hydral and Nuclear power plants. 23. Explain the advantages of interconnected system. 24. Explain the working principle and applications of solar power plant. 25. Explain the principle of operation of wind power station. 26. Explain the basic principle of biomass energy source. 27. Explain the principle of operation of fuel cell. 28. Explain the comparison of fuel cell. UNIT II PART - A 12. State Kelvin's law. 13. What are the elements used in transmission line? 14. State the different types of supports used in transmission line. 15. Expand the term ACSR. 16. What is sag in transmission line? 17. Write span lengths allowable for RCC poles. 18. State the usual spans allowed in the various types of supports. 19. What is skin effect? 20. What is ferranti effect? 21. State the classification of overhead transmission lines. 22. What is meant by transmission efficiency of transmission line? 23. What is meant by regulation of transmission line? 24. What is corona? 25. Write the expression for corona loss. 26. State the different types of DC link used in HVDC system. PART - B 11. Draw and explain the typical layout of AC power supply scheme. 12. State and explain Kelvin's law. 13. Write the limitations of Kelvin's law. 14. Explain regulation and efficiency of transmission lines. 15. Explain the effect of wind and ice loading in transmission lines. 16. Explain transposition of transmission lines.

13 17. What is meant by skin effect and write the factors on which it depends. 18. Draw the schematic diagram of different types of links used in HVDC transmission. 19. State the advantages of HVDC transmission. 20. An overhead line has a span of 200 metre the line conductor weight 824 kg/metre. Calculate the maximum sag in the line, if the maximum allowable tension in the line is 1500 kg. 21. Calculate the sag when the supports are at equal levels. also explain the effect of wind and ice on sag. 22. An overhead line has a span of 250m between level supports. The conductor weight is 700kg/km. Calculate the maximum sag if the ultimate tension of the conductor is 6000kg. Assume factor of safety as What is corona? and explain the corona formation in transmission lines. 24. State the advantages and disadvantages of corona. UNIT III PART - A 18. What is the purpose of insulator? 19. State the different types of insulators. 20. State the reasons for failure of insulators. 21. What are the tests adopted in insulators? 22. What is string efficiency? 23. State the methods for improving the string efficiency. 24. State the classifications of cables based on voltage. 25. State the methods of laying the cables. 26. What is grading of cables? 27. What are the faults occur in the cable? 28. Name the two types of grading of cables. 29. Name the types of pressure cables. PART - B 8. Explain the causes of failure of insulators. Explain the flash over test conducted on insulators. 9. Define string efficiency for insulators. 10. Explain impulse frequency flash over test on insulators. 11. State the properties required for the insulating materials. List out the advantages of UG cables. 12. What are the advantages and disadvantages of oil filled cables.

14 13. Explain capacitance grading of UG cables. 14. Explain open circuit fault, short circuit fault and earth fault. 15. Write about the grading of cables. 16. Explain the construction of different types of insulators. 17. Explain the causes of failure of insulators. 18. Explain the various methods of testing of insulators. 19. Explain the construction of belted cable. 20. Explain the construction advantages and disadvantages of oil filled cable. 21. Explain different types of laying of cables. 22. How to locate the short circuit and open circuit fault by Murray loop test. 23. Explain any one suspension type of insulator with neat diagram. Discuss its merits and demerits. UNIT IV PART - A 15. What is switch gear? 16. What are the essential features of switch gear? 17. What are the faults in a power system? 18. What is symmetrical faults in power system? 19. What is unsymmetrical faults in power system? 20. What is circuit breaker? 21. What is Arc voltage? 22. What is recovery voltage? 23. What is restriking voltage? 24. What is rate of rise of restriking voltage? 25. What is current chopping? 26. What is short time rating? 27. What is the function of a fuse? 28. What are the desirable characteristics of fuse element? 29. What are the types of fuses? 30. What is meant by lightning? 31. What is voltage surge? 32. What are the protective devices used for protection against lighting? 33. Explain resistance switching. 34. What are the advantages of SF6 circuit breaker.

15 9. Explain the features of switch gear. PART - B 10. Explain the faults in a power system. 11. Explain the working principle of circuit breaker. 12. Explain the arc phenomenon in circuit breaker. 13. Explain the construction and working axial blast air circuit breaker. 14. Explain the construction and working principle of Sulphur Hexa Fluoride circuit breaker and state its advantages. 15. Explain the schematic diagram of HVDC circuit breaker producing current zero. 16. Explain the construction and working of semi enclosed rewirable fuse. 17. Explain the construction and working of HRC fuse with tripping device. 18. Explain the direct stroke and indirect stroke. 19. Explain the construction and working of Expulsion type lightning arrester. 20. Explain the construction and working of gapless arrester. UNIT V PART - A 12. What is static relay? 13. What are the types of static relays? 14. What is meant by grounding or earthing? 15. What are the basic elements of static relay? 16. List the fundamental requirements of relays. 17. What is neutral grounding? 18. What is meant by definite time lag relay? 19. What is primary and backup protection? 20. List the types of neutral grounding. 21. What are the advantages of neutral grounding? PART - B 8. Briefly explain the function of protective relay. 9. Explain the main requirements of good protective relay. 10. Explain with neat sketch the construction and working principle of induction type over current relay. 11. Explain the construction and working principle of earth leakage relay.

16 12. Explain the construction and working of two types of differential relays. 13. Explain the block diagram the operating principle of smart over current relay. 14. Explain the construction and working principle of differential over current relay. 15. Explain the operation of smart Mho relay. 16. Explain with sketch solid grounding. 17. Explain with sketch resistance grounding. 18. Explain with sketch reactance grounding. 19. Explain with sketch resonant grounding. 20. Explain the construction and working principle of grounding transformer. 21. Explain equipment grounding. 22. Explain the underground neutral system.

17 PERIYAR CENTENARY POLYTECHNIC COLLEGE Periyar Nagar, Vallam , Thanjavur AUTONOMOUS INSTITUTION DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING QUESTION BANK III YEAR/V SEM SPECIAL ELECTRICAL MACHINES UNIT - I PERMANENT MAGNET SYNCRONOUS MOTOR PART-A 1. State the difference between permanent magnet motor and pure reluctance motor. 2. Write the torque equation of permanent synchronous motor. 3 What type of supply is given to the permanent magnet synchronous motor? 4. List any one application of synchronous reluctance motor. 5. State any two properties of synchronous reluctance motor. 6. Write the emf equation of permanent magnet synchronous motor 7. Mention any two advantages of pure reluctance motor. 8. State any one application of permanent magnet synchronous motor. 9. What is permanent magnet synchronous motor? PART-B 1. Explain the construction and working principle of permanent synchronous motor. 2. Derive from the first principles the emf equation of permanent magnet synchronous motor. 3. Derive the torque equation of permanent magnet synchronous motor. 4. Draw and explain the phasor diagram of permanent magnet synchronous motor. 5. Draw and explain the speed-torque characteristics of permanent magnet synchronous motor. 6. Explain the microprocessor based control for permanent magnet synchronous motor. 7. Explain the construction and working principle of synchronous reluctance motor. 8. Draw and explain the characteristics of synchronous reluctance motor.

18 UNIT II SWITCHED RELUCTANCE MOTOR PART-A 1. What is the principle of switched reluctance motor? 2. Give any two applications of SRM. 3. State any two advantages of SRM. 4. What do you meant by switched reluctance motor? 5. Draw the speed-torque characteristics of srm. 6. Write the expression of torque in srm. 7. State the names of power controller circuits used in srm. 8. Give the relationship between-fundamental switching frequency and speed of srm. PART-B 1. Explain the construction of srm. 2. Explain the working principle of srm. 3. Explain how static torque is produced in srm. 4. Explain the construction and working principle of srm. 5. Draw and explain the srm drive circuits for 3 phase srm. 6. Explain the working of any one power controller circuits for srm. 7. Explain the torque-speed characteristics of srm. 8. Explain the torque prediction of srm. 9. Explain the sensor less operation of srm. UNIT III STEPPER MOTORS PART-A 1. Mention the different types of stepper motor. 2. Define step angle as applied to stepper motor. 3. What is hybrid stepper motor. 4. Draw the dynamic characteristics of stepper motor. 5. Mention the few applications of stepper motor. 6. State the principle of stepper motor. 7. Define the holding torque as applied to static characteristics of stepper motor. 8. Write the expression for reluctance torque in stepper motor. 9. What is permanent magnet stepper motor?

19 PART-B 1. Explain the construction and working of variable stepper motor. 2. Explain the construction and working of hybrid stepper motor. 3. Explain the construction and working of permanent magnet stepper motor. 4 Derive the reluctance torque produced in stepper motor. 5. Explain the speed torque characteristics of stepper motor. 6. Draw the block diagram of closed loop of stepper motor and explain. 7. Explain any five applications of stepper motor UNIT IV PERMANENT MAGNET BRUSHLESS DC MOTORS PART-A 1. Name the materials used for permanent magnet. 2. Draw the demagnetization characteristics curve of permanent magnet. 3. Write the expression for emf equation of pmbl dc motor. 4. Write the expression for torque equation of pmbl dc motor. 5. Mention the any two applications of pmbl dc motor. 6. Draw the b-h curve of permanent magnet. 7. What are the types of permanent brushless dc motor? 8. What are the salient features of brushless dc motor? 9. What are the disadvantages of brushless dc motor as compared to pmdc commutator motor? 10. Compare pmbl dc motor with conventional dc motor. PART-B 1. Explain the working principle of pmbl dc motor. 2. Derive the emf equation of pmbl dc motor. 3. Derive the torque equation of pmbl dc motor. 4. Draw the explain the speed-torque characteristics of brushless dc motor. 5. With neat sketches and explain the operation brushless dc motor with 180 degree magnetic arc. 6. With neat sketches and explain the operation of brushless dc motor with 120 degree magnetic arc. 7. Draw the explain functions of controller for brushless dc motor.

20 UNIT V OTHER SPECIAL MACHINES PART-A 1. Which type of supply is used in hysteresis motor. 2. Where is linear motor used. 3. Mention the application of a.c series motor. 4. State the principle of permanent magnet d.c motor. 5. What is the type of supply used in permanent magnet a.c motor. 6. What is linear motor. 7. Give an application of permanent magnet d.c motor. 8. State the principle of hysteresis motor. 9. State the applications of hysteresis motor. 10. State the difference between the linear induction motor and conventional induction motor. 11. State the applications of permanent magnet ac motor. PART-B 1. Briefly explain the principle of operation and characteristics of hysteresis motor. 2. Explain the principle of operation and characteristics of a.c series motor. 3. Explain the principle of operation of linear induction motor. 4. Explain the construction and working of permanent magnet d.c motor. 5. Explain the construction and working of permanent magnet a.c motor. 6. Write short notes on Linear motor A.c series motor 7. Write short notes as Permanent magnet a.c motor Linear motor