D.C. Generators MCQ Questions & Answers | Electrical Engineering

Shunt generators are most suited for stable parallel operation due to their drooping voltage characteristics.

Option A: Rising voltage characteristics

Rising voltage characteristics are not suitable for parallel operation as they could cause instability, leading to one generator taking more load than others.

Option B: Identical voltage characteristics

Identical voltage characteristics are desirable for parallel operation, but in practice, it's challenging to achieve exact identical voltage, making this option less feasible.

Option C: Drooping voltage characteristics

Drooping voltage characteristics are ideal for parallel operation as they ensure that as the load increases, the voltage decreases slightly, allowing for automatic load sharing between generators.

Option D: Linear voltage characteristics

Linear voltage characteristics do not provide the necessary voltage drop needed for stable load sharing in parallel operation.

Conclusion:

Shunt generators with drooping voltage characteristics are most suited for stable parallel operation because they facilitate effective load sharing between generators.

Voltage regulation in a D.C. generator refers to the change in terminal voltage from no-load to full-load, expressed as a percentage of the full-load voltage.

A lower percentage of voltage regulation indicates better performance because it means the generator maintains a more constant voltage under varying load conditions.

Option A: 100% regulation

100% regulation would mean that the voltage drops to zero under full load, which is highly undesirable.

Option B: Infinite regulation

Infinite regulation implies a complete loss of voltage under load, which is not practical or acceptable.

Option C: 50% regulation

50% regulation indicates a significant drop in voltage under load, which is also not preferred as it would lead to poor performance.

Option D: 1% regulation

1% regulation is ideal as it indicates very little voltage drop under load, ensuring that the generator provides a stable voltage output.

Conclusion:

Among the given options, 1% regulation is preferred because it reflects the best performance in maintaining a constant voltage.