BT-104 (GS) – Basic Electrical and Electronics Engineering

B.Tech. I & II Semester
Examination, June 2023
Grading System (GS)
Max Marks: 70 | Time: 3 Hours

Note:
i) Attempt any five questions.
ii) All questions carry equal marks.

Previous Year Questions (June 2023)

Q.1

a) Using the mesh analysis, find the $I_o$ in the circuit as given below. (Unit 1)

A circuit with three meshes for analysis. Mesh 1 (bottom-left) contains a 16V source and is defined by current Io. It shares a 4-ohm resistor with Mesh 3 and a 2-ohm resistor with Mesh 2. Mesh 2 (bottom-right) has a dependent current source of 10 times Io. Mesh 3 (top) contains a 6-ohm and an 8-ohm resistor.

b) In the figure below, find the current flowing through $R_1$ using Thevenin's Theorem. (Unit 1)

A circuit for Thevenin's theorem. A central T-network of resistors consists of a 2-ohm resistor (R1) at the top, a 3-ohm resistor (R2) on the left, and a 4-ohm resistor (R3) on the right. A 6V source is connected on the left side of the network, and a 3A current source is on the right side.
Q.2

a) What do you understand by Source. Discuss about different types of Dependent and Independent Voltage and current Sources with suitable sketch. (Unit 1)

b) Define the following: (Unit 2)

i) Alternating Quantity

ii) R.M.S. Value

iii) Average value

iv) Form factor.

v) Peak factor
Q.3

a) A coil having a resistance of 10 ohms and an inductance of 0.2H is connected in series with a $100 \times 10^{-6}$ F capacitor across a 230V, 50Hz supply, Calculate: (Unit 2)

i) The active and reactive components of the current

ii) The voltage across the coil, Draw the phasor diagram.

b) A balanced star connected load of $8 + 6j$ ohm is connected across three phase, 50Hz, 440V supply system. Calculate: (Unit 2)

i) Line current

ii) Power absorbed

iii) Reactive volt ampere
Q.4

a) State the different types of transformers. Describe the construction and general principle of transformer. (Unit 3)

b) What do you understand by Self inductance and mutual inductance? Derive the relation between Self inductance and Mutual Inductance. (Unit 3)
Q.5

a) Open circuit and short circuit test on a single phase transformer gave the following results: $V_0=200V, I_0=0.7A, W_0=20$ Watt Test from primary side. $V_s=10V, I_s=10A, W_s=40$ Watt test from secondary side. Determine the equivalent circuit parameters referred to primary side. (Unit 3)

b) Explain the construction and working principle of three phase induction motor with suitable diagram. (Unit 4)
Q.6

a) A three phase, 6 pole, 50 Hz induction motor has a slip of 1% at no load and 3% at full load, Find: (Unit 4)

i) Synchronous Speed

ii) No Load Speed

iii) Full Load Speed

iv) Frequency of rotor current at full load.

b) Discuss about types of losses occurring in electrical machine. (Unit 4)
Q.7

a) Draw and explain the V-I characteristics of a PN junction. (Unit 5)

b) Draw the circuit and explain the characteristics of CB configuration. (Unit 5)
Q.8

Write a short note on any two :

i) RS Flip Flop (Unit 5)

ii) Star Delta Transformation (Unit 1)

iii) De Morgan's Theorem (Unit 5)

iv) Torque-Slip Characteristics (Unit 4)