4A251 CDC Set B Vol 1 Questions and
Answers Already Passed
What is the primary purpose of a transformer in an electrical system?
✔✔ To change the voltage level of alternating current (AC) power.
How does a transformer work to increase or decrease voltage?
✔✔ By using two coils, a primary and secondary, that are magnetically coupled.
What is the difference between a step-up and step-down transformer?
✔✔ A step-up transformer increases voltage, while a step-down transformer decreases it.
Why are transformers essential for long-distance electrical transmission?
✔✔ They allow voltage to be stepped up for efficient transmission and stepped down for safe
usage.
What material is typically used for the core of a transformer, and why?
✔✔ Iron is used because it is highly magnetic, helping to efficiently transfer energy between
coils.
1
,What is the role of the primary winding in a transformer?
✔✔ To receive input voltage from the power source and create a magnetic field.
What is the function of the secondary winding in a transformer?
✔✔ To receive the magnetic energy and convert it back into electrical energy with the desired
voltage.
Why is transformer efficiency important in power distribution?
✔✔ Higher efficiency reduces energy loss during voltage conversion, improving overall system
performance.
What is the relationship between the number of turns in the primary and secondary coils in a
transformer?
✔✔ The voltage ratio between the primary and secondary windings is directly proportional to the
ratio of the number of turns.
How does an autotransformer differ from a traditional transformer?
2
, ✔✔ An autotransformer shares a common winding for both the primary and secondary, making
it more compact and efficient for certain applications.
What happens to the voltage if a transformer has more turns in the secondary coil than in the
primary?
✔✔ The voltage is stepped up, increasing the output voltage.
Why do transformers often have cooling systems, such as oil or air cooling?
✔✔ To prevent overheating, which could damage the insulation and reduce the lifespan of the
transformer.
What is the principle of mutual induction in a transformer?
✔✔ The change in current in the primary coil creates a changing magnetic field, which induces a
voltage in the secondary coil.
What is a common cause of transformer failure?
✔✔ Overloading, which can lead to overheating and damage to the windings and insulation.
Why is it important to ground a transformer?
3
Answers Already Passed
What is the primary purpose of a transformer in an electrical system?
✔✔ To change the voltage level of alternating current (AC) power.
How does a transformer work to increase or decrease voltage?
✔✔ By using two coils, a primary and secondary, that are magnetically coupled.
What is the difference between a step-up and step-down transformer?
✔✔ A step-up transformer increases voltage, while a step-down transformer decreases it.
Why are transformers essential for long-distance electrical transmission?
✔✔ They allow voltage to be stepped up for efficient transmission and stepped down for safe
usage.
What material is typically used for the core of a transformer, and why?
✔✔ Iron is used because it is highly magnetic, helping to efficiently transfer energy between
coils.
1
,What is the role of the primary winding in a transformer?
✔✔ To receive input voltage from the power source and create a magnetic field.
What is the function of the secondary winding in a transformer?
✔✔ To receive the magnetic energy and convert it back into electrical energy with the desired
voltage.
Why is transformer efficiency important in power distribution?
✔✔ Higher efficiency reduces energy loss during voltage conversion, improving overall system
performance.
What is the relationship between the number of turns in the primary and secondary coils in a
transformer?
✔✔ The voltage ratio between the primary and secondary windings is directly proportional to the
ratio of the number of turns.
How does an autotransformer differ from a traditional transformer?
2
, ✔✔ An autotransformer shares a common winding for both the primary and secondary, making
it more compact and efficient for certain applications.
What happens to the voltage if a transformer has more turns in the secondary coil than in the
primary?
✔✔ The voltage is stepped up, increasing the output voltage.
Why do transformers often have cooling systems, such as oil or air cooling?
✔✔ To prevent overheating, which could damage the insulation and reduce the lifespan of the
transformer.
What is the principle of mutual induction in a transformer?
✔✔ The change in current in the primary coil creates a changing magnetic field, which induces a
voltage in the secondary coil.
What is a common cause of transformer failure?
✔✔ Overloading, which can lead to overheating and damage to the windings and insulation.
Why is it important to ground a transformer?
3
