Q1: Pressure gauges are never connected directly to the live steam line; rather a loop or syphon is interposed as close as possible to the pressure gauge. This is done to

ANS:C - both 'a' & 'b'.

The correct answer is: both 'a' & 'b'. Pressure gauges are not directly connected to live steam lines due to several reasons:

1. Avoiding overheating: By interposing a loop or syphon close to the pressure gauge, the temperature of the medium reaching the gauge is reduced. This helps in preventing overheating of the tubes and bellows which operate the gauge, minimizing errors and potential damage due to excessive heat.
2. Forming a seal of water by steam condensate: The loop or syphon allows for the condensation of steam into water. This water forms a seal that fills the tube or bellows at the pressure being measured. This helps in accurately transmitting the pressure to the gauge while preventing the direct contact of high-temperature steam with the sensitive components of the gauge.

So, both reasons 'a' and 'b' are valid explanations for why pressure gauges are not directly connected to live steam lines. The other option mentioned, avoiding the static head error introduced by steam entry, is not the primary reason for using a loop or syphon in this context.