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**51) **Which of the following gas has the highest calorific value?

**Answer is:**

## Coal gas

**Related KPCL AE Mechanical Question Paper - 2018 with Answer Key**

**Answer is:**

### v/T = constant, if p is kept constant

**Answer is:**

### All of these

**Explanation:**

The entropy may be expressed as a function of

* pressure and temperature

* temperature and volume

* heat and work

**Answer is:**

### Mach number

**Explanation:**

Bulk Modulus is a measure of the resistance of a fluid to compression. It is defined as the ratio of pressure stress to volumetric strain.

The value of bulk modulus of a fluid is required to determine Mach number. Mach number (M or Ma) is a dimensionless quantity. It represents the flow of velocity beyond the boundary when compared to the local speed of sound. It is used to determine the resistance of fluid or gas in its compressed state.