Q1: Multistage compression of air as compared to single stage compression offers the advantage of

ANS:D - all (a), (b) & (c).

Multistage compression of air, compared to single-stage compression, offers the advantage of all (a), (b), and (c):

1. Power saving per unit weight of air delivered: Multistage compression allows for higher overall compression ratios to be achieved by dividing the total compression into multiple stages. This results in each stage requiring less work compared to a single-stage compressor handling the same compression ratio. As a result, multistage compression generally offers power savings per unit weight of air delivered.
2. Moisture elimination in the inter-stage cooler: Multistage compression allows for the intercooling of air between stages, typically using intercoolers. These intercoolers reduce the temperature of the compressed air between stages, which helps to condense and remove moisture from the air. Removing moisture is important for preventing damage to downstream equipment and for ensuring the quality of the compressed air.
3. Increased volumetric efficiency: Multistage compression can improve volumetric efficiency compared to single-stage compression. By dividing the compression into multiple stages, each stage can operate with a lower compression ratio, reducing the impact of heat generation and improving volumetric efficiency. This allows for a higher volume of air to be compressed per unit of power input.