### Star Delta Transformation mcqs in network theorem

The star-delta transformation preserves the **__** of the circuit.

a) Power factor

b) Voltage

c) Current

d) Resistance

Answer: c) Current

Explanation: The star-delta transformation preserves the current in the circuit. The total current remains the same before and after the transformation.

The star-delta transformation is applicable to circuits containing **__**.

a) Only resistors

b) Only capacitors

c) Only inductors

d) Resistors, capacitors, and inductors

Answer: d) Resistors, capacitors, and inductors

Explanation: The star-delta transformation can be applied to circuits containing resistors, capacitors, and inductors or any combination thereof.

The star-delta transformation is most commonly used in **__** circuits.

a) Single-phase

b) Three-phase

c) Digital communication

d) Audio

Answer: b) Three-phas

Explanation: The star-delta transformation is most commonly used in three-phase circuits to convert between star and delta configurations.

The star-delta transformation is based on the concept of **__**.

a) Kirchhoff’s Laws

b) Faraday’s Law

c) Ampere’s Law

d) Ohm’s Law

Answer: a) Kirchhoff’s Laws

Explanation: The star-delta transformation is based on the application of Kirchhoff’s Laws to simplify circuit analysis.

The number of impedances in the star configuration is **__** the number of impedances in the delta configuration.

a) Equal to

b) Less than

c) Greater than

d) Unrelated to

Answer: b) Less than

Explanation: The number of impedances in the star configuration is less than the number of impedances in the delta configuration.

The star-delta transformation can be used to convert a **_ circuit to a _** circuit.

a) Parallel, series

b) Series, parallel

c) Capacitive, inductive

d) None of the above

Answer: b) Series, parallel

Explanation: The star-delta transformation can be used to convert a series circuit to a parallel circuit.

The star-delta transformation is used to simplify calculations involving **__**.

a) Power factor correction

b) Voltage regulation

c) Power dissipation

d) Complex impedances

Answer: d) Complex impedances

Explanation: The star-delta transformation is used to simplify calculations involving complex impedances in AC circuits.

In the star-delta transformation, the impedance in the delta configuration is equal to the impedance in the star configuration **__**.

a) Divided by √3

b) Multiplied by √3

c) Divided by 3

d) Multiplied by 3

Answer: a) Divided by √3

Explanation: In the star-delta transformation, the impedance in the delta configuration is equal to the impedance in the star configuration divided by √3.

The star-delta transformation is an example of a **__** transformation.

a) Voltage-current

b) Current-voltage

c) Impedance-resistance

d) Resistance-impedance

Answer: a) Voltage-current

Explanation: The star-delta transformation is an example of a voltage-current transformation, as it involves converting between voltage and current representations.

The star-delta transformation simplifies circuit analysis by reducing the number of **__** in the circuit.

a) Resistors

b) Inductors

c) Capacitors

d) Unknown variables

Answer: d) Unknown variables

Explanation: The star-delta transformation simplifies circuit analysis by reducing the number of unknown variables in the circuit.

The star-delta transformation is reversible, meaning that a delta configuration can be converted back to a star configuration.

a) True

b) False

Answer: a) True

Explanation: The star-delta transformation is reversible, and a delta configuration can be converted back to a star configuration using the same principles.

The star-delta transformation is particularly beneficial for analyzing circuits with **__**.

a) High voltage levels

b) High current levels

c) Balanced loads

d) Unbalanced loads

Answer: c) Balanced loads

Explanation: The star-delta transformation is particularly beneficial for analyzing circuits with balanced loads, where the impedances are evenly distributed.

The star-delta transformation is commonly used in **__** systems.

a) Power distribution

b) Telecommunications

c) Control systems

d) All of the above

Answer: d) All of the above

Explanation: The star-delta transformation is commonly used in power distribution systems, telecommunications, control systems, and various other applications.

The star-delta transformation is commonly applied in **__** circuits.

a) AC circuits

b) DC circuits

c) Series circuits

d) Parallel circuits

Answer: a) AC circuits

Explanation: The star-delta transformation is commonly applied in AC circuits to simplify calculations and analysis.

In the star-delta transformation, the impedance values in the star configuration are related to the impedance values in the delta configuration by a multiplication factor of **__**.

a) √3

b) 1/√3

c) 3

d) 1/3

Answer: b) 1/√3

Explanation: In the star-delta transformation, the impedance values in the star configuration are related to the impedance values in the delta configuration by a multiplication factor of 1/√3.