Basic Electrical Engineering Interview Questions 2

• Briefly explain the purpose of Inductor in an electric circuit?

An inductor is a piece of conducting wire generally wrapped around a core of a ferromagnetic material. Like capacitors, they are employed as filters as well but the most well known application is their use in AC transformers or power supplies that converts AC voltage levels.

• What do you mean by dependent and independent voltage sources?

In general, there are two main types of DC sources
1. Independent (Voltage and Current) Sources
2. Dependent (Voltage and Current) Sources

An independent source produces its own voltage and current through some chemical reaction and does not depend on any other voltage or current variable in the circuit.
The output of a dependent source, on the other hand, is subject to a certain parameter (voltage or current) change in a circuit element. Herein, the discussion shall be confined to independent sources only.

• Differentiate between ideal and non-ideal voltage sources?

The Ideal Voltage Source An ideal voltage source which has a terminal voltage which is independent of the variations in load. In other words, for an ideal voltage source, the supply current alters with changes in load but the terminal voltage, VL always remains constant.Non-Ideal or Practical Voltage Source For a practical source, the terminal voltage falls off with an increase in load current.

• What does the term “Voltage Regulation” means?

Voltage regulation (VR) is an important measure of the quality of a source. It is used to measure the variation in terminal voltage between no load (IL =0, open circuit) and full load (IL = IFL)

• What is DC Current source? Differentiate between ideal and non ideal current sources?

A current source, unlike the DC voltage source, is not a physical reality. How ever,   it i s useful in deriving equivalent circuit models of semiconductor devices such as a transistor. It can also be subdivided
into ideal and non-ideal categories.
The Ideal Current Source By definition, an ideal current source, that produces a current which is independent of the variations in load. In other words the current supplied by an ideal current source does not change with the load voltage.
Non-Ideal or Practical Current Source The current delivered by a practical current source falls off with an increase in load or load voltage.

• What id difference between power and energy?

Energy is defined as the capacity of a physical system to perform work. In the context of electric circuits, energy (w) is related to power by the following relationship
p = vi =dw/dt
So the difference is that power is the rate of change of energy.