JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II ELEMENTS OF ELECTRICAL AND ELECTRONICS ENGINEERING Previous Question Paper (April/May - 2023 - R13)
Note: i) Question paper consists of Part A, Part B.
ii) Part A is compulsory, which carries 25 marks. In Part A, Answer all questions.
iii) In Part B, Answer any one question from each unit. Each question carries 10 marks and may have a, b as sub questions.
Part A
State Ohm’s Law.
Answer
Ohm's Law states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, provided the temperature and other physical conditions remain constant.
What is the importance of 3-point starter?
Answer
A 3-point starter is essential for DC shunt and compound motors to limit the high starting current, which could otherwise damage the armature windings. It provides protection against low voltage (No-Volt Coil) and excessive current (Overload Release), ensuring the motor starts safely and reaches its rated speed gradually.
What are the differences between ideal and practical transformers?
Answer
Sign in to view the complete answer paper.
Define Slip and Slip speed.
Answer
Sign in to view the complete answer paper.
Why PMMC instruments used for DC quantity measurements only?
Answer
Sign in to view the complete answer paper.
Classification of measuring instruments.
Answer
Sign in to view the complete answer paper.
Write the difference between diode and SCR.
Answer
Sign in to view the complete answer paper.
What are the applications of SCR?
Answer
Sign in to view the complete answer paper.
Define sensitivity.
Answer
Sign in to view the complete answer paper.
Write the applications of CRO.
Answer
Sign in to view the complete answer paper.
Part B
Find the current through 10 Ω resistor using Kirchhoff’s Voltage law.
Answer
Sign in to view the complete answer paper.
Find the current through 20 Ω resistor using Kirchhoff’s Current Law.
Answer
Sign in to view the complete answer paper.
Derive the torque equation of DC motor.
Answer
Sign in to view the complete answer paper.
A 220 V dc motor has an armature resistance of 0.75 Ω. Calculate the induced emf in the motor if it is drawing an armature current of 30 A.
Answer
Sign in to view the complete answer paper.
What are the losses of a single-phase transformer?
Answer
Sign in to view the complete answer paper.
A 2000/200 V, 20 kVA transformer has 66 turns in the secondary. Calculate (i) Primary turns, (ii) Primary and Secondary currents.
Answer
Sign in to view the complete answer paper.
Explain the operation principle of 3-phase induction motor.
Answer
Sign in to view the complete answer paper.
A 50 Hz, 4-pole, 3-phase induction motor has a rotor current of frequency 2 Hz. Determine the slip and speed of the motor.
Answer
Sign in to view the complete answer paper.
Derive the equation for deflection of a PMMC in spring controlled.
Answer
Sign in to view the complete answer paper.
List different types of static errors of a PMMC measuring instrument.
Answer
Sign in to view the complete answer paper.
Why is damping required for a measuring instrument?
Answer
Sign in to view the complete answer paper.
Enlist the advantages of MI instrument.
Answer
Sign in to view the complete answer paper.
Discuss the operation principle of half wave rectifier with neat diagrams.
Answer
Sign in to view the complete answer paper.
An a.c. supply of 230 V is applied to a half-wave rectifier circuit through a transformer of turn ratio 10:1. Find (i) the output d.c. voltage and (ii) the peak inverse voltage. Assume the diode to be ideal.
Answer
Sign in to view the complete answer paper.
Explain the principle of operation of NPN transistor.
Answer
Sign in to view the complete answer paper.
Discuss the difference between NPN and PNP transistors.
Answer
Sign in to view the complete answer paper.
Draw CRO circuit diagram and explain the role of each part in the diagram.
Answer
Sign in to view the complete answer paper.
What is the function of X – Y mode on CRO front panel?
Answer
Sign in to view the complete answer paper.
List out the standard specifications of CRO.
Answer
Sign in to view the complete answer paper.