K. S. POLYTECHNIC, BANGALORE-109

DEPARTMENT OF MECHANICAL ENGINEERING

IMPORTANT QUESTIONS FOR EXAMINATION

SUBJECT :-BASIC ELECTRICAL AND ELECTRONICS ENGINEERING

SEMESTER :-2ND SEMESTER

SUBJECT INCHARGE :- SRINIVAS V SURPALI

UNIT 1

ELECTRICITY AND DC CIRCUITS:

5 Marks Questions :-

1 ) What are the Sources of Electrical Energy.

2 ) Write the Effects of Electric Current & The applications of electrical Energy.

3 ) Define The terms , Conductors, Insulators, & Semi Conductors & give Examples for each.

4 ) Write Ohm’s Law, Applications & Limitations.

5 ) Define & Write the Units of, Power & Energy.

10 Marks Questions :-

1 ) A) Derive The Equation for Total Resistance Where 3 Resistance R1, R2 & R3 Connected in Series.

B) 3 Resistances of 5ohm, 10ohm & 20ohms are connected in series across 100v Supply Find

i) Effective Resistance ii) Total Current iii) Voltage Drop across each Resistance

2 ) A) Write the Unit & Meters Used for the , Current, Voltage , EMF , Power & Energy.

B) 2 Lamps of 100watts are used for 4 hours daily. Find Monthly Consumption bill if the rate per unit is Rs 2.

UNIT 2

ELECTROMAGNETISM:

5 Marks Questions :-

  1. Define with SI units. i) Flux density ii) Reluctance.
  2. Define with SI units. i) Magnetic flux ii) Magneto Motive Force.
  3. Define with SI units i) Permeability ii) Reluctance.
  4. Define with SI units a) Inductance b) Mutual inductance
  5. Distinguish between self-induced and mutual-induced e.m.f.
  6. Explain with a sketch statically induced emf with an example.
  7. Explain with a sketch dynamically induced emf with an example

10 Marks Questions :-

1) State Faraday’s First and Second Laws of Electromagnetic Induction

2) Explain the construction of DC Generator.

3) Explain the working of a DC Generator.

UNIT 3

FUNDAMENTALS OF AC CIRCUITS:

5Marks Questions :-

1 Define i) RMS value ii) Average value and write equations.

2 Define the following with reference to a sinusoidal waveform

a)Maximum value

b)Instantaneous value

c)Form factor.

3 Define with equations, i) Capacitive reactance ii) Inductive reactance.

4 What is a transformer? State its applications.

5 What is an AC generator? State its applications.

5Define with SI units. i) Frequency and ii) Time period

10 Marks Questions :-

  1. Explain the construction of an AC Generator.

State the working principle of a transformer.

  1. A resistance of 100 Ω is connected in series with a capacitance of 150 μF. If

this is connected to a 200 V, 50 Hz supply, FindCapacitive reactance.

Impedance of the circuit, Power factor, and Current.

A resistance of 20 is connected in series with a inductance of 0.07 H . If this is

connected to a 200V, 50 Hz supply, find Inductive reactance, Impedance,

Power factor, and current

3Compare between three phase power supply and single phase power supply.

State Five advantages of three phase power supply over single phase power

supply.

UNIT-4

ELECTRIC MOTOR DRIVES

5Marks Questions :-

  1. Write the classifications of dc motors ( With Diagram)
  2. What are AC Motors? Write their classification &Applications.
  3. Write the selection Criteria of AE Moters.
  4. What are FHP motors & Write their applications.
  5. Write applications 3phase motor.

10 Marks Questions :-

1A) Write the applications of DC motors.

1B) Write name plate details of 3phase motor.

2A) List the motors used for following applications i) Textile industry II) Cement industry III) Mining Industry.

2B) Write advantages 3phase motors over 1phase motors (ANY FIVE)

3A) What are mechanical enclosures & Write its necessity.

3B) Write the classification as mechanical enclosures.

UNIT-5

PROTECTIVE DEVICES, UPS AND ESTIMATION

5Marks Questions :-

1)What are protective device? Write its necessity.

2)How protective devices are classified.

3)What is Fuse? Write its classifications.

4)What are cells? Write its classifications giving examples.

5)What is UPS? Write its necesity & classification.

10 Marks Questions :-

1A) Draw neat construction diagram of HRC Fuse , Label parts.

1B) Draw neat diagram of rewirable fuse, label parts.

2A) Write the conditions of fully charged & Discharged batteries.

2B) What are SMF & Write their applications.

3) Plan & estimate the cost of electrical wiring of 3m X 3m room consisting 2 tube lights & one fan.

4) Plan & estimate electrical wiring for one lathe machine using Mcb, iron clad switches & HRC fuse .

UNIT-6

ELECTRONIC COMPONENTS AND APPLICATIONS

5Marks Questions :-

1)What areIntrinsic and Extrinsic semiconductors.

2)Show with circuit diagram i) Forward bias ii) Reverse bias as PN Junction diode.

3)Write the types & applications of diode.

4)What are transistors write their types with symbol.

5)Write the applications of transistors.

10 Marks Questions :-

1A) Draw the neat diagram of half wave rectifier & explain its working.

1B) Draw the construction of full wave bridge rectifier & show its wave forms.

2A) explain the working of zenerdiode as a voltage regulator.

2B) Explain the working of SCR.

3A) What are logic gates? Write the symbol & truth table of all the gates.

3B) Draw neat diagram of electromagnetic relay & label the parts.