Basic Electrical & Electronics Engineering (BT-104) - Important Questions

Use mesh analysis to determine mesh currents / branch current $I_0$ in the given DC network

Apply the superposition theorem to find voltage, current or power in a circuit

State and explain Kirchhoff's current law (KCL) and Kirchhoff's voltage law (KVL) with suitable example.

Explain the Star-Delta transformation with a suitable example.

Explain dependent and independent voltage and current sources with neat sketches, including conversion between voltage and current sources.

Find the current in the $2\Omega$ resistor in the given circuit

State and explain the superposition theorem

Find the current flowing through a resistor using Thevenin's theorem.

Using nodal analysis, find the current through the $10\Omega$ resistor

Find the voltage $V_{ab}$ in the given network

Define RMS value, average value, form factor, peak factor and related alternating quantity terms, and give their values for a sinusoidal waveform.

Numerical on series R-L-C circuit to find inductive reactance, capacitive reactance, impedance, current, power factor, power and voltages.

For a 3-phase balanced supply feeding a delta-connected load with phase impedance $(3.54+j3.54)\Omega$ at 110V, determine the line currents and draw the phasor diagram.

Numerical on series R-L circuit to find current, voltages across resistor and inductor, power factor and real power.

Explain the role of resistance, capacitance and inductance in an electric circuit.

Discuss active (real) power, reactive power, apparent power and power factor in an AC / series RLC circuit.

Numerical on series R-L-C circuit to find active and reactive components of current and voltage across the coil, with phasor diagram.

Derive expressions for impedance, current, power factor and power in R-L-C series circuit.

A balanced star connected load of $8 + 6j\text{ ohm}$ is connected across three phase, $50\text{Hz}, 440\text{V}$ supply system. Calculate i) Line current ii) Power absorbed iii) Reactive volt ampere

Draw phasor diagrams for series R-L-C circuit for $X_L > X_C$, $X_L < X_C$ and $X_L = X_C$.

Compare power and find phase and line voltages and currents when the same 3-phase load is connected in delta versus star.

Draw the phasor diagram of a 3-phase star-connected load and derive the relations between phase and line voltages and currents.

Explain Faraday's laws of electromagnetic induction.

Determine equivalent circuit parameters referred to primary from open-circuit and short-circuit test data.

What do you understand by self inductance and mutual inductance? Derive the relation between self inductance and mutual inductance.

Explain the working principle of a single-phase transformer.

Calculate transformer efficiency at full load from iron and copper losses.

Draw and explain the typical normal magnetization curve / magnetization characteristics of ferromagnetic material.

State the types of transformers and describe construction and general principle.

Calculate number of turns using primary-secondary voltage turns ratio.

Derive an expression for an energy density in magnetic circuits.

What tests are required to determine efficiency, voltage regulation and temperature rise of transformer windings and insulation?

Find number of turns in each winding from voltage ratio, frequency and maximum core flux using the emf equation.

Enumerate the various losses in a transformer and how they can be minimized.

Describe the construction and main parts of a D.C. machine with suitable sketches/schematic diagram.

Explain the principle of operation of a 3-phase induction motor.

For a three-phase induction motor, calculate synchronous speed $N_s=120f/P$, rotor speed $N=(1-s)N_s$, slip $s$, and rotor current frequency $f_r = s f$ (including rotor emf if given turn ratio).

Explain / discuss the types of losses occurring in electrical machines.

Discuss the construction and working principle of a three-phase induction motor, draw its torque-slip characteristic, and explain why it cannot operate at synchronous speed.

Explain the construction and working principle of a three-phase induction motor with suitable diagram.

Draw and explain the complete Torque-slip characteristics of 3 phase induction motor.

Calculate efficiency of 3-phase induction motor from given losses, shaft power and slip.

Explain in detail the Applications of DC Machines.

Explain the construction and working principle of a three-phase induction motor with suitable diagram.

Explain the torque-speed characteristic and speed control of a separately excited DC motor.

Explain the difference between a separately excited and a self-excited DC generator.

Draw and explain the V-I characteristics of a PN junction diode.

Draw the circuit and explain the working principle and characteristics of transistor in common base configuration

Explain the operation of BJT in common emitter configuration with the help of input and output characteristics

Write short notes on any two of the following: i) Logic gates ii) R-S flip flop iii) Compare electric and magnetic circuit iv) B-H curve

Write short notes on any two of: R-S flip-flop, Star-Delta transformation, De Morgan's theorem, and related topic (J-K flip-flop / Torque-slip characteristics).

Solve for $x$

Write a short note on any Two. i) J-K Flip Flop ii) Dependent and Independent Sources iii) Open circuit and short circuit test iv) De-Morgan's Theorem

What do you understand by Adder circuit? Draw and explain the working principle of full adder circuit.

In a fixed bias circuit using n-p-n transistor, find the operating point if $V_{CC} = 24\text{V}$, $R_B = 220\text{k}$, $R_C = 4.7\text{k}$.

Explain principle of operation and characteristics of BJT.