Test: Basics of IC Engine - 1 - Mechanical Engineering MCQ

Except gas turbine, all are SC engine. GT is EC engine.

Most high speed compression engines operate on Dual combustion cycle.

Cylinder block: It is the main supporting structure for the various components.
Inlet and exhaust valve: Regulate the incoming and outgoing charge to and form the cylinder.

Piston: It acts as moving boundary of the combustion system and forms the first link to transmit the gas force through connecting rod.

The balance weights are provided for static and dynamic balancing of the rotating system.

• Rocker Arm: The rocker arm is a part of the valve train system that helps in opening and closing the intake and exhaust valves.


• Follower: The follower is another crucial component that follows the profile of the camshaft to actuate the valves.


• Cams: Cams are the lobes on the camshaft that push the followers to open and close the valves at the right time.


• Camshaft: The camshaft houses the cams and rotates to operate the valves through the followers.

The valve train system in an IC Engine is responsible for controlling the opening and closing of the intake and exhaust valves. It consists of various components that work together to ensure proper timing and operation of the valves. In this case, all the parts mentioned - rocker arm, follower, cams, and camshaft - are integral components of the valve train system. The rocker arm helps in transmitting the motion from the camshaft to the valves, the follower follows the camshaft profile to actuate the valves, the cams provide the necessary push to open and close the valves, and the camshaft houses the cams and rotates to operate the valves. Therefore, option B (1, 2, 3, and 4) is the correct answer as all these components constitute the valve train system.

In internal combustion engines, the gudgeon pin (UK, wrist pin or piston pin US) connects the piston to the connecting rod, and provides a bearing for the connecting rod to pivot upon as the piston moves.

• Maximum Pressure: This parameter indicates the highest pressure reached during the engine cycle and is important for determining the strength and durability of the engine.



• Fuel Consumption: This parameter measures how efficiently the engine uses fuel to generate power. Lower fuel consumption is desirable as it indicates better fuel efficiency.



• Mean Effective Pressure: This parameter is a measure of the average pressure exerted on the piston during the entire engine cycle. It is a key indicator of the engine's performance and efficiency.



• Unit Power: Unit power refers to the power output of the engine per unit of displacement or volume. It is important for comparing the power output of engines with different cylinder dimensions.

• Mean Effective Pressure is a comprehensive parameter that takes into account the overall performance and efficiency of the engine.



• It provides a more balanced comparison between engines of different cylinder dimensions, power, and speed.



• By considering the average pressure exerted on the piston throughout the engine cycle, Mean Effective Pressure offers a more accurate representation of the engine's performance compared to other parameters like maximum pressure or unit power.



• Therefore, choosing Mean Effective Pressure as the basis of comparison allows for a more informed evaluation of the engines and their overall efficiency.

• Statement 2: Volumetric efficiency is maximum at inlet mach number of 0.5.


• Statement 3: Inlet valve mach index is related to volumetric efficiency.

• Statement 2 is correct because volumetric efficiency is indeed maximum at an inlet mach number of 0.5.


• Statement 3 is also correct as the inlet valve mach index is directly related to volumetric efficiency.