ELECTRICAL CIRCUITS AND INSTRUMENTATION

ELECTRICAL CIRCUITS AND INSTRUMENTATION QUESTION BANK UNIT- I PART A 1. Define current 2. Define voltage 3. Define resistance 4. Define conductance 5. Define power 6. State Ohm s law 7. State Kirchoff s laws 8. State Thevenin s theorem 9. State Superposition theorem 10. State maximum power transfer theorem 11. Define energy. 12. Write down the formula for the power given is the voltage and resistance. 13. What is he condition to obtain maximum power in an electric circuit 14. Calculate the current and resistance of a 50W, 100V electric bulb. 15. Find the cross sectional area given R=0.24Ω, l=700m, ρ=2.83 10-8 Ω m. PART B 1. State and explain Ohm s law. 2. State the KVL and KCL and explain. 3. Write step-by-step procedure to find out the current in a particular branch by applying Thevenin s Theorem. 4. Write step-by-step procedure to find out the current in a particular branch by applying Norton s Theorem. 5. Find the equivalent resistance when two resistances are connected in parallel. 6. Find the equivalent resistance when three resistances are connected in series. 7. State and explain super position theorem 8. State and explain Thevenin s theorem. 9. State and explain Norton s theorem 10. In the circuit given below, find the current in 10 Ω resistor and verify super position theorem. Pg.no(1.55)-prob: 12 11. Find the voltage across 15Ω resistor by Thevenin s theorem Pg.no: (1.56) prob.no: 13 12. Find the voltage across 15Ω resistor by Norton s theorem Pg.no: (1.56) prob.no: 14 13. A Wheatstone network has the following resistances in various branches AB= 10 Ω, BC=15Ω CD=25Ω, A=20Ω, BD=10Ω. A cell of 2 V is connected across AC. Calculate the current in the branch BD. Pg.no: (1.55) prob.no: 11 UNIT- II PART A 1. What is the power factor for an A.C. circuit with pure resistor only? 2. What is the power factor for an A.C. circuit with pure inductor?

3. What is the power factor for an A.C. circuit with pure capacitor? 4. What is the formula for the current in the ac circuit with pure inductor? 5. What is the formula for the current in the ac circuit with pure resistor? 6. What is the formula for the current in the ac circuit with pure capacitor? 7. What is impedance? 8. Define admittance. 9. Define reactance 10. Define susceptance 11. Define conductance 12. A voltage of 100 V at 50 Hz is applied across a pure inductor of 0.04 H. find the current. 13. What is the impedance for R-L series circuit? 14. What are the two types to solve the parallel circuit? 15. What is meant by resonance? 16. What is the condition for the resonance? 17. What are the types of resonance? 18. Define Q factor 19. What are the applications of resonance? 20. Compare series and parallel resonance. PART B 1. (a) Derive the expression for the average power in ac circuit through pure inductor (b) A series circuit has R=10 Ω, L= 50 mh and C=100µF and supplied with 200 V, 50 C/s. Find (i)impedance, (ii)current, (iii)power, (iv)power factor, (v)voltage drop across each element. 2. Derive the expression for power in R-L-C series circuit. 3. Derive an expression for the impedance in R-L series circuit. 4. (a) Derive the Q factor of series resonant circuit. (b) Define and derive the bandwidth of series resonant circuit. 5. (a)define and derive the Q-factor of parallel resonant circuit. (b) Compare series and parallel resonance 6. (a) Derive the expression for the impedance in an R-C series circuit (b) Derive an expression for frequency at series resonance. 7. (a) What is the condition for parallel resonance? Derive an expression for frequency at resonance. (b) A series circuit contains a resistance of 5 ohms and inductance of 0.4 H and a variable capacitor across 100 V, 50 Hz supply. Find (i) the capacitance for getting resonance (ii) the p.d. across inductance and capacitance (iii) the Q-factor of the series circuit.

UNIT-III Part- A 1. Define transformer 2. What are the parts of a transformer? 3. Define an ideal transformer. 4. What are the types of transformer? 5. What is the e.m.f equation of a transformer? 6. What is voltage transformation ratio? 7. What are the ideal characteristics of an ideal transformer? 8. What are determined using open circuit test on transformer? 9. What are the losses in a transformer? 10. Define efficiency of a transformer. 11. What is meant by regulation? 12. Write any two applications of a transformer. 13. Define DC generator 14. State the principle by which a DC machine works. 15. What is the material used to make the brushes? 16. What are the types of armature windings? 17. What are the various types of DC generator? 18. Define DC motor 19. What are the various types of DC motors? 20. Define induction motor. 21. Define back emf 22. Write the applications of a DC generator. 23. Define stepper motor. 24. Write the applications of a DC motor. 25. Write the applications of a stepper motor. PART- B 1. Explain the construction and working principle of a single phase transformer. 2. (a) Derive the e.m.f equation of a transformer. (b)define transformer. Explain in detail the types of transformer. 3. (a) Derive the condition for maximum efficiency of a transformer. (b) Explain the types of losses that occur in a transformer 4. Explain the Open Circuit test and Short Circuit test of a transformer. 5. Explain theprinciple of operation of a DC. Generator 6. Explain the types of DC generator 7. Explain the construction of a DC.Machine 8. Explain the types of DC motor. 9. Explain about capacitor start induction motor 10. Explain stepper motor.

UNIT-IV Part- A 1. Define indicating instruments. 2. Mention the basic forces requires for operation of indicating instruments. 3. What are the effects used to produce the deflecting force? 4. What are the methods to provide controlling force? 5. What are the types of damping? 6. What is shunt? 7. What is multiplier? 8. Write the formulae for shunt and multiplier resistances. 9. State the purpose of shunt resistor in PMMC ammeter. 10. What is the principle of PMMC instrument? 11. Write the equation for the deflecting torque. 12. What are the advantages of PMMC instruments? 13. Define voltmeter sensitivity. 14. State the types of bridges. 15. State any two applications of Wheatstone bridge. 16. List out the types of CRO 17. What is the use of time base generator in CRO? 18. What is the use of CRO probe? 19. State any two uses of CRO. 20. What are the applications of CRO? 21. Compare dual trace and dual beam CRO. 22. What are the advantages of digital storage oscilloscope? PART-B 1. (a) Explain various operating forces required in indicating instruments. (b) Explain with aneat sketch the operation of Wheatstone bridge. 2. (a) Explain any one method of controlling force. (b) Compare dual trace and dual beam CRO. 3. What is a PMMC instrument. Explain with diagram the construction and working of PMMC instrument. 4. Explain how a basic PMMC instrument can be converted into ammeter and voltmeter circuit? 5. Mention the various universal impedance bridge arrangement to measure R,L,and C with neat sketch. 6. Draw the block diagram of CRO and explain its operation. 7. Explain the working of electrostatic focusing arrangements used in CRO. 8. Explain the working of electrostatic deflection arrangements used in CRO. 9. Explain the operation of vertical deflection system and mention the applications of CRO. 10. Explain with a neat sketch the construction and working of dual trace CRO. 11. Explain with a neat sketch the construction of CRT. 12. Explain the construction and working of dual trace CRO. 13. Explain the construction and working of dual beam CRO.

14. Explain the construction and working of digital storage oscilloscope

PART-A PART-B UNIT-V 1. Define recorders 2. What are the types of recorders? 3. Mention the applications of X-Y recorders 4. What are the applications of strip chart recorders? 5. Define transducer. 6. What are the types of transducer? 7. Define strain gauge. 8. What are the types of strain gauge? 9. Name any two photo electric transducer. 10. Give one difference between XY recorder and strip chart recorder. 11. What is LVDT? 12. State any two applications of LVDT. 13. What is meant by load cell? 14. State any two applications of load cell. 15. State any two applications of thermistor. 16. What are the types of DVM? 17. Give the materials used to manufacture thermistors. 18. What is meant by thermocouple? 19. What is NTC thermistor? 20. What is PTC thermistor? 21. What is data acquisition system? 1. Explain with a neat sketch the construction and working of X-Y recorder. 2. Explain with a neat sketch the construction and working of strip-chart recorder. 3. Explain with a neat sketch the construction and working of photo electric transducer. 4. Explain the construction and working of load cell. 5. Explain the operation of LVDT and mention its applications. 6. What is a thermocouple? Explain seeback effect in thermocouple. 7. What is a thermocouple? Explain how to measure the temperature by using thermocouple. 8. What is a thermistor? Mention its various forms with neat sketch. 9. Explain with block diagram the working of digital voltmeter. 10. Explain the principle of operation of digital frequency counter. 11. Explain PC based DAS with block diagram.

PERIYAR CENTENARY POLYTECHNIC COLLEGE PERIYAR NAGAR-VALLAM-THANJAVUR-613403 DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING ELECTRONIC DEVICES AND CIRCUITS UNIT I Part-A 1. What are active components? 2. What are passive components? 3. What is resistor? 4. What is capacitor? 5. Define Inductor. 6. Define semiconductor. 7. What are the types of semiconductor? 8. Define drift current. 9. Define diffusion current. 10. Define peak inverse voltage. 11. Define reverse recovery time. 12. Draw the symbol for zener diode. 13. What is rectifier? 14. Define ripple factor. 15. Mention the various types of rectifiers. 16. Mention the various types of filters. 17. Define filter. 18. Define cut-in voltage. 19. Define rectifier efficiency. 20. How many diodes used in bridge rectifier. Part-B 1. Explain the working principle of PN junction diode. 2. Explain the working principle of zener diode. 3. Draw the circuit and explain the operation of fullwave rectifier. 4. Draw the circuit and explain the operation of bridge rectifier. 5. Explain the two types of breakdown occurred in zener diode. 6. With the diagram explain the operation of inductor filter. 7. With the diagram explain the operation of LC filter. UNIT II PART A 1. Define transistor biasing. 2. Draw the symbols of NPN and PNP transistors. 3. Mention the importance of biasing circuits. 4. Mention various types of biasing circuits. 5. Mention the three types of transistor configurations. 6. Define current gain. 7. Define output impedance.

8. Define band width. 9. What is feedback? State the gain of negative feedback amplifier. Define amplifier. Mention the applications of emitter follower. PART B 1. With the diagram explain the voltage divider bias. 2. With the neat diagram explain the fixed bias. 3. Draw and explain the frequency response curve of RC coupled amplifier. 4. What are the advantages of negative feedback? 5. With the diagram explain how is transistor used as a switch. 6. Explain the operation of emitter follower. 7. With the diagram explain the operation of a NPN transistor. 8. Explain the operation and input and output characteristics of common emitter circuit. 9. Explain the three types of transistor biasing with suitable diagram. 10. Draw the circuit diagram of RC coupled amplifier and explain the operation. UNIT III PART - A 1. Define oscillator. 2. What are the three parts of oscillators? 3. Mention the different types of oscillators. 4. What are the advantages of RC phase shift oscillator? 5. Define drain resistance of FET. 6. State the amplification factor of JFET. 7. Define the terms unipolar and bipolar. 8. Draw the symbol for n channel MOSFET. 9. Draw the equivalent circuit of UJT. 10. State the advantages of crystal oscillator. 11. What is Barkhausen criterion? 12. Define intrinsic stand-off ratio. 13. What are the difference between amplifier and oscillator? PART - B 1. How oscillators are classified? 2. Derive the expression for condition of oscillation.

3. Explain the general form of oscillator. 4. Draw and explain the equivalent circuit of UJT. 5. Explain the characteristics of UJT. 6. With the diagram explain the operation of Hartley oscillator. 7. Draw the circuit of colpitts oscillator and explain its operation. 8. Draw and explain the operation of RC Phase shift oscillator. 9. With the diagram explain the operation of crystal oscillator. 10. With the diagram explain the operation of JFET. 11. With the diagram explain the operation of common source amplifier. 12. Draw the circuit of FET as chopper and explain its operation. 13. Draw and explain the operation of UJT relaxation oscillator. 14. Explain the operation and characteristics of UJT and also explain the different regions. UNIT IV PART A 1. Define thyristor. 2. Draw the symbol of SCR. 3. State the application of SCR. 4. Define break-over voltage of SCR. 5. Define holding current of SCR. 6. Draw the symbols of DIAC and TRIAC. 7. State the applications of TRIAC. PART B 1. How can SCR acts as switch. 2. Explain the operation of DIAC as bidirectional switch. 3. With the diagram explain the speed control of fan using DIAC and TRIAC. 4. Draw and explain the two transistor analogy of SCR. 5. Explain how SCR is used as a controlled rectifier. 6. Mention the specifications of SCR. 7. Draw the circuit of IGBT as a switch and explain its operation. 8. With the diagram explain the working principle of SCR. 9. With the diagram explain the construction details and working principle of DIAC. 10. Explain the working principle of TRIAC with neat diagram. 11. Explain the working principle of MOSFET with neat diagram. 12. Explain the working principle of IGBT with neat diagram.

UNIT - V PART - A 1. Draw the symbol of 7 segment LED. 2. Write the uses of opto coupler. 3. State the applications of LDR. 4. Expand LDR? 5. What are the advantages of LCD? 6. Expand LCD? 7. Define opto coupler. 8. Define clipper and clamper. 9. Mention the various types of clippers. 10. Define multivibrators. 11. Mention the various types of multivibrators. 12. What are the two types of LCD? 13. What is meant by DC restorer? PART B 1. How a solar cell converts solar energy to electrical energy? 2. With the neat diagram explain the working principle of LDR. 3. Explain the working principle of LED with neat sketch. 4. Explain opto interrupter with neat diagram. 5. With the diagram explain optical transmitter using infrared LED. 6. With the diagram explain optical receiver. 7. Explain avalanche photo diode with diagram. 8. Explain the working principle of LCD with diagram. 9. Explain the working principle of opto coupler with diagram. 10. Explain the working principle of photo transistor with diagram. 11. With the neat diagram explain the operations of various types of diode clipper circuits. 12. With the neat diagram explain the operations of various types of diode clamper circuits. 13. With the diagram explain the operation of the voltage doubler. 14. Draw the circuit of astable multivibrator and explain its operation. 15. Draw the circuit of monostable multivibrator and explain its operation. 16. Draw the circuit of bistable multivibrator and explain its operation.

PERIYAR CENTENARY POLYTECHNIC COLLEGE PERIYAR NAGAR-VALLAM-THANJAVUR-613403 DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING C Programming Unit-1 Part-A(1 mark) 1. Define program. 2. What is program development cycle? 3. What is a program language? 4. Define algorithm. 5. What is flow chart? 6. What are the two types of declaration? 7. What is the use of global declaration? 8. What are the character set used in c? 9. Define keyword. 10. What is meant by c token? 11. What are the types of tokens? 12. What is mean by identifiers? 13. What is c constant? 14. What are the types of c constant? 15. What is variable? 16. What are the two types of arithmetic operators? 17. What are binary operators? 18. What are unary operators? 19. Define expression. 20. What are the types of expression? 21. Define type casting. 22. Write the types of type casting. 23. What is the use of scan f function? 24. What is the use of print f function? Part-B (12mark) 1. Explain program development cycle. 2. Briefly discuss about programming language. 3. List the features of good programming language. 4. Explain the flow chart symbols. 5. Give the advantages and limitations of flow chart. 6. Give the algorithm and flow chart for finding the largest Number among three numbers. 7. Write any 3 features of c program. 8. Explain basic data type in c program. 9. Explain basic data types in c &its modifiers. 10. Explain operators. 11. Explain data type modifiers. 12. How to declares variable with example & give the uses of declaration. 13. Write a program to factorial of n numbers. 14. Write the program to find sum& average of n numbers. 15. Explain typecasting & its type. 16. Explain the formatted input function.

17. Explain the formatted output function. 18. Explain operator s procedure & associativity. 19. Draw the flowchart to find the product of first N natural numbers. 20. Write a c program to find the biggest number between given three numbers using a single statement by using conditional operator. 21.Expain structure of C program UNIT-II Part-A(1 mark) 1. What is entry loop? 2. What is exit control loop? 3. Write the Syntax for for loop. 4. What is the use of break statement? 5. What is the significance of continue statement. 6. Define Array. 7. What is the general form for declaring an array? 8. How to initialize an array? 9. Define string. 10. How to declare an 2D array? 11. How to declare a string? 12. What are the functions used to read the string? (Get string as I/P) 13. Define strlen () function. 14. Write some string manipulation functions. 15. What is meant by null string? 16. What is meant by multidimensional array? 17. Difference between while &do while loop. 18. What is the use of go to statement? Part-B(12mark) 1. Difference between exit control loop & entry control loop example. 2. Explain for loop. 3. Explain Nested if statement with example. 4. Explain Switch case with example. 5. What is subscripted variable & write its rules. 6. Explain one D array. 7. Explain 1-D & 2-D array processing with example. 8. Write a program to arrange N given numbers in ascending order. 9. Explain string handling functions. 10. Write a program to add two given matrices. 11. Write a program to multiply given matrices. 12. Write a program to print the Fibonacci series up to 100. 13. Write a c program to find whether the given word is palindrome or not. UNIT-III Part-A(1 mark) 1. Give any three functions is math.h. 2. What is the use of getche () functions. 3. Define gets () function. 4. Give the general forms of ellipse () function.

5. Define function. 6. What are the types of function? 7. What are the 2 parts in function definition? 8. What is the use of return statement? 9. What is meant by void function? 10. How to declare a function? 11. What are types of function calls? 12. What is meant b scope of variable? 13. What is mean by lifetime of variable? 14. What are the storage classes? 15. What is the keyword used to indicate automatic variable? 16. Define structure 17. Write syntax to declare a structure (). 18. How can we access the structure members? 19. Write the syntax to access the members in structure> 20. Define union. Part-B(12mark) 1. Explain any three functions in stdio.h with example. 2. Give the need for user defined function 3. Explain pointers with examples. 4. With example explain call by value. 5. Explain call by reference with example. 6. Explain recursion. 7. Give the difference between array & structure. 8. Explain structure definition with example. 9. How will you create structure variable? How will the data are to structure variable give example. 10. Explain union with example. 11. Write a program to print our data of birth using a structure. 12. Explain about parameter passing methods with examples. 13. Define a structure tag population with fields men& women. Create structure within Structure using state & population structure. Read & display data. UNIT-4 Part-A(1 mark) 1. Define pointer or pointer variable. 2. What are the two operators used in pointers? 3. How to declare a pointer? 4. How to assign the address to a variable? 5. What is pointer expression? 6. What is memory allocation? 7. Define static memory allocation. 8. What are the types of memory allocation? 9. Define dynamic memory allocation. 10. Write the Syntax or general form of malloc. 11. Write the advantages of pointers. 12. Define scale factor. 13. What is the relationship between pointers and array.

Part-B(12mark) 1. Define pointer and give its advantages. 2. With example explain how the address of the variable is assigned to a pointer. 3. Explain increment and scale factor in pointers. 4. Give the relation between array and pointers. 5. Explain pointers and functions with example. 6. Explain function returning pointers. 7. Describe pointers to pointers. 8. Explain the various dynamic memory allocation functions with simple example. 9. Using pointers, reverse the given integer array of N elements. 10. Write a program to demonstrate realloc () function. UNIT -5 Part-A(1 mark) 1Give the general form of F12 definition. 2Give the general form of opening a file. 3Define scan 'f () function. 4Define ferror() function. 5What is random access file? 6Define fseek() function. 7Define command-line arguments. 8What is preprocessor? 9Give the general form of #define. 10Define file inclusion directive 11Give the general form of #ifdef.#enddef. Part-B(12mark) 1)Explain macro substitution. 2)Explain file inclution. 3)Mention the various compiler controlled directives and their uses. 4)Define a file. How a file in opened and closed? 5)Explain the various I/O operations on files. 6)How to handle errors during I/O operatins? 7)Explain the use of command line arguments. 8)Explain about random access files. 9)How will you append items to a file? 10)How to open and close file? Explain different modes of files. 11)Give a text file,write a program to create another text file deleting the words a, an, the and replacing each one of them with a blank space. OCT-2012 PART-A(1 mark) 1. Define identifier. 2. List any twp escape sequences character in C 3. Draw any two flowchart symbols 4. List the basic data types used in C program 5. Give the syntax for elseif ladder 6. Define one dimensional array 7. Write down the uses of array. 8. Compare Break and Continue statement

9. Define Recursion 10. Write down the categories of function 11. What is union? 12. What is the use of auto keyword? 13. What is the use of & operato? 14. What is the use of free() function? 15. Write short notes on scale factor in array. 16. Define dynamic memory allocation. 17. Write down the syntax for closing a file. 18. What is file inclusion? 19. State the types of macro substitution directory. 20. What are the different modes of opening a file? Part-B(12mark) 21.a)(i) State the features of good programming languages (ii) List down the operators and its precendence level in C (OR) b) (i) Explain formatted I?O statements (ii) Write down the C program to find factorial of a given number. 22.a)(i) Explain Switch case statement with suitable example (ii)write a program to find sum of N numbers using array. (OR) b) (i) Explain the if else statement with example program. (ii) Explain string handling function 23.a)(i)What is meant by call by reference? Explain. (ii)explain structures within structures (OR) b(i) Explain array of structures. (ii) Discuss about standard I/O functions. 24.a)(i)Explain malloc(),calloc() and realloc() functions (ii)explain Linked list with example (OR) b.(i) Explain pointer declaration and pointer initialization (ii) Discuss about pointer expressions 25.a)(i) Explain the methods of error handling during I/O operation (ii) Discuss about random access file function (OR) B (i)write a program to read five names from keyboard and print the same using Command line arguments (ii) Explain Preprocessor directives PREPARED BY APPROVED BY

STAFF IN-CHARGE HEAD OF THE DEPARTMENT 21. A) Write a program to print our data of birth using a structure. Give the difference between array & structure.4 [OR] B) Explain call by reference with example. Explain recursion. 22) A) Explain pointers with examples. Explain union with example. [OR] Define a structure tag population with fields men& women. Create structure within structure using state & population structure. Read & display data.8 B) With example explain how the address of the variable is assigned to a pointer. 23) A) Explain increment and scale factor in pointers. Define pointer and give its advantages. [OR] B) Explain the various dynamic memory allocation functions with simple example. Discuss about pointer expressions4