Single Phase Transformer Questions and Answers for Viva

Answer-1: A transformer is an electrical device that transfers electrical energy from one circuit to another through electromagnetic induction.

Answer-2: The primary components of a single-phase transformer are the primary and secondary windings, and a magnetic core.

Answer-3: Transformers operate based on the principles of electromagnetic induction, where alternating current in the primary winding induces a changing magnetic field, which in turn induces a voltage in the secondary winding.

Answer-4: The primary winding in a single-phase transformer is connected to the input voltage source and is responsible for receiving the electrical energy.

Answer-5: The secondary winding in a single-phase transformer is connected to the load and is responsible for delivering the electrical energy.

Answer-6: The magnetic core provides a low reluctance path for the magnetic flux generated by the primary winding, enhancing the efficiency of energy transfer.

Answer-7: The turns ratio of a transformer is the ratio of the number of turns in the primary winding to the number of turns in the secondary winding.

Answer-8: The voltage ratio of a transformer is directly proportional to its turns ratio. For example, if the turns ratio is 1:2, the voltage ratio will be 1:2 as well.

Answer-9: The different types of single-phase transformer connections include the step-up, step-down, and isolation configurations.

Answer-10: The step-up configuration in a single-phase transformer increases the voltage from the primary winding to the secondary winding.

Answer-11: The step-down configuration in a single-phase transformer decreases the voltage from the primary winding to the secondary winding.

Answer-12: The isolation configuration in a single-phase transformer provides electrical isolation between the primary and secondary windings, ensuring safety and preventing ground loops.

Answer-13: Efficiency of a transformer can be defined as the output power divided by the input power. That is efficiency = output / input .

Answer-14: The factors that affect the efficiency of a single-phase transformer include core losses, winding resistance, and load impedance.

Answer-15: The voltage regulation of a single-phase transformer is the percentage change in output voltage from no-load to full-load conditions.

Answer-16: Standard voltage ratings for transformers include 120V, 240V, 480V on the primary side, and various voltages on the secondary side depending on application.

Answer-17: Transformers are cooled using methods such as natural convection, forced air cooling, or liquid cooling (using oil or other dielectric fluids).

Answer-18: Common applications include voltage conversion for residential and commercial use, power distribution, and isolation.

Answer-19: Transformers can be connected in parallel to increase capacity or redundancy, but connecting them in series is not common due to impedance matching issues.

Answer-20: Autotransformers are transformers where the primary and secondary windings are connected electrically, allowing for voltage conversion with fewer windings, resulting in smaller size and weight compared to conventional transformers.