Match column A with column B.

Column A		Column B
A.	Mechanical efficiency	1.	Ratio of brake power to indicated power
B.	Indicated thermal  efficiency	2.	Ratio of actual volume to swept volume
C.	Volumetric efficiency	3.	Ratio of indicated power to fuel power

Explanation:

Engine Performance Parameter :

Indicated Power:

It is the power developed inside the engine cylinder.

\(ip = \frac{{{p_m}LAN.n}}{{60}}\)

Brake Power:

This is the actual power available at the crankshaft and may be called power output of the engine. It is always less than indicated power.

\(BP = \frac{{2\pi NT}}{{60}}\)

Indicated thermal efficiency :

It is the ratio of IP to fuel power.

\({\eta _i} = \frac{{ip}}{{{{\dot m}_f} \times CV}}\)

Brake thermal efficiency :

It is the ratio of bp to fuel power.

\({\eta _b} = \frac{{bp}}{{{{\dot m}_f} \times CV}}\)

Mechanical efficiency is defined as the ratio of brake power (delivered power) to the indicated power (power provided to the piston).

\({\eta _m} = \frac{{bp}}{{ip}} = \frac{{bp}}{{bp + fp}}\)

Mechanical efficiency takes into account the mechanical losses in an engine.

Volumetric efficiency is defined as the ratio of actual volume flow rate of air into the system to the rate at which the volume is displaced by the system.

It indicates the breathing capacity of the system. It is to be noted that the utilization of the air is that determines the power output of the engine. Intake system must be designed in such a way that the engine must be able to take in as much air as possible.