Practical Viva Questions Basic Electrical & Electronics Engineering (BEEE)

Summary

This video covers 20 fundamental electrical and electronics engineering viva questions and answers, focusing on key concepts such as electrical supply types, Kirchhoff's laws, active and passive elements, inductive and capacitive reactance, and different forms of power. The video provides clear explanations of essential topics like electric current, voltage, impedance, frequency, RMS values, and the power factor. It is an excellent resource for students preparing for exams or those seeking to reinforce their understanding of electrical principles, offering both theoretical knowledge and practical applications.

Takeaways

• 😀 Electrical supply in homes is alternating current (AC).
• 😀 The standard voltage rating for home electrical supply is 230V, with a current rating of 5 to 15 Amps.
• 😀 There are two main types of electrical sources: AC and DC (Direct Current).
• 😀 Internal resistance refers to the resistance within the source itself; it is in series for voltage sources and in parallel for current sources.
• 😀 Kirchhoff's Current Law (KCL) states that the algebraic sum of currents meeting at a node is zero.
• 😀 Kirchhoff's Voltage Law (KVL) states that the sum of voltages around a closed loop equals zero.
• 😀 Electric current is the flow of electrons through a conductor.
• 😀 Electric potential (voltage) is the work done in moving a unit positive charge from infinity to a point.
• 😀 Passive elements like resistors, capacitors, and inductors do not have their own electromotive force (EMF).
• 😀 Active elements like voltage and current sources have their own EMF and supply power to the circuit.

Q & A

What type of electrical supply is used in our homes?

The electrical supply used in our homes is AC (Alternating Current) supply.

What is the rating of the electrical supply used in our homes?

The rating of the electrical supply in our homes is 230 volts with current ratings of 5 to 15 amperes.

What are the two main types of electrical sources?

The two main types of electrical sources are AC (Alternating Current) sources and DC (Direct Current) sources.

What is the internal resistance of an electrical source?

Internal resistance refers to the resistance within the source itself. In voltage sources, it is connected in series, while in current sources, it is connected in parallel.

What does Kirchhoff’s Current Law (KCL) state?

Kirchhoff's Current Law (KCL) states that the algebraic sum of currents meeting at any node in a circuit is zero.

Can you explain Kirchhoff’s Voltage Law (KVL)?

Kirchhoff’s Voltage Law (KVL) states that the sum of all voltages, including EMF and voltage drops, around a closed loop is zero.

What is the definition of electric current?

Electric current is the flow of electrons through a conductor.

What is meant by electric potential or voltage?

Electric potential (or voltage) is the work done in bringing a unit positive charge from infinity to a point in an electric field.

What is the difference between passive and active elements in a circuit?

Passive elements do not generate their own EMF (e.g., resistors, capacitors, inductors), while active elements do generate their own EMF (e.g., voltage sources, current sources).

What is inductive reactance?

Inductive reactance is the opposition to changes in current due to the inductance of a component. It resists the flow of alternating current.

What is the RMS value of voltage and current?

The RMS (Root Mean Square) value is the square root of the average of the squares of the instantaneous values of voltage or current, representing the effective value of alternating current.

What is reactive power in an electrical circuit?

Reactive power is the power that oscillates between the source and the load, but is not consumed in the circuit. It arises due to inductance and capacitance.

What is the power factor and how is it calculated?

The power factor is the cosine of the angle between the voltage and current waveforms. It indicates how effectively the current is being converted into useful power.

What is the peak value of voltage or current?

The peak value is the maximum value reached by the voltage or current waveform during one complete cycle.