# Electrical Engineering Interview Question And Answer-Basic Electrical Part 1

Q. What is an Electric circuit?
A. An
electric circuit is an inter connection of electrical elements.

### Q. What do you mean by independent and dependent sources?

A. An
ideal independent source is an active element that provides a specified voltage
or current that is completely independent of other circuit variables where as
an ideal dependent source is an active element in which the source quantity is
controlled by another voltage or current.

### Q. What are the types of dependent sources?

A.1.Voltage
controlled voltage source
2. Current
controlled voltage source
3. Voltage
controlled current source
4. Current
controlled current source

### Q. Explain ohm’s law?

A. At
constant temperature, current flowing through an element is directly proportional
to the potential difference across it.

### Q. What is open circuit and short circuit?

A. An open
circuit is a circuit element approaching infinite resistance and short circuit
is a circuit element with resistance approaching zero.

### Q. Define a branch, node, loop and mesh?

A. Branch:
It represents a single element such as voltage source or resistor.
Node: A
node is the point of connection between two or more branches
Loop: A
loop is any closed path in a circuit
Mesh: A
mesh is a loop which does not contain any other loops in it.

### Q. State kirchhoff’s laws?

A. Kirchhoff’s
current law: It states that algebraic sum of currents entering a node is zero.
i.e Sum of
currents entering a node=sum of currents leaving it.
Kirchhoff’s
voltage law: It states that algebraic sum of voltages around a closed path or
loop is zero.
i.e sum of
voltage drops=sum of voltage rises.

### Q. What is super node and super mesh?

A. A super
node is formed by enclosing a voltage source between two non-reference nodes
and any elements connected parallel with it. A super mesh results when two
meshes have a current source in common.

### Q. Mesh analysis vs Nodal analysis?

A. Mesh
analysis is more useful when there are many series elements, voltage sources
and we have to find out branch or mesh currents.
Nodal
analysis is better if there are many parallel connected elements, current
sources and we have to find node voltages.

### Q. Explain superposition principle?

A. The
superposition principle states that the voltage across (or current through) an
element in a linear circuit is the algebraic sum of voltages across (or
currents through) that element due to independent sources acting alone.

### Q. What is meant by source transformation?

A. A
source transformation is the process of replacing a voltage source Vs.
in series with a resistor R by a current source is in parallel with
a resistor R, or vice versa.

### Q. State thevenin’s theorem?

A.
Thevenin’s theorem states that a linear two terminal circuit can be replaced by
an equivalent circuit consisting of a voltage source VTH in series
with a resistor RTH where VTH is open circuit voltage at
the terminals and RTH is the input or equivalent resistance at the
terminals when the independent sources are turned off.

### Q. State Norton’s theorem?

A.
Norton’s theorem states that a linear two terminal circuit can be replaced by
an equivalent circuit consisting of a current source IN in parallel
with a resistor RN where IN is short circuit current
through the terminals and RN is the input or equivalent resistance
at the terminals when the independent sources are turned off.

### Q. State maximum power transfer theorem?

A. Maximum
resistance as seen from the load.

### Q. Explain the behavior of capacitor and inductor to D.C?

A. A
capacitor acts as an open circuit to D.C
We know
that Q=CV
i=dQ/dt
i=CdV/dt
dV/dt is
zero in case of D.C supply. So current is zero which implies it acts as an open
circuit.
An
inductor acts as a short circuit to D.C
We know
that V=Ldi/dt
di/dt=0 in
case of D.C supply. So, voltage across inductor is zero which implies it acts
as a short circuit.

### Q. What are different parameters used to represent two port networks?

A.A two
port network can be modeled using six parameters
Impedance
(Z),Admittance (Y),Hybrid (h),Inverse hybrid (g),Transmission (T) and Inverse
transmission (t) parameters.