Which of the mentioned below is not a component of the IC engine?
Piston
Cylinder
Wheel
Spark Plug
Wheel is not a component of the internal combustion engine (IC engine).
While the wheel plays a crucial role in a vehicle powered by an IC engine, it's not part of the engine itself. The wheel receives the power generated by the engine and transmits it to the ground, enabling the vehicle to move. However, the IC engine comprises various internal components like pistons, cylinders, spark plugs, etc., responsible for converting fuel into heat energy and then into mechanical power.
Pick the wrong statement:
Two-stroke engine can run in any direction.
In four-stroke engine, a power stroke is obtained in four-strokes.
Petrol engine occupy more space than diesel engine for same power output.
Thermal efficiency of four-stroke engine is more due to positive scavenging.
The wrong statement is: Thermal efficiency of four-stroke engine is more due to positive scavenging.
Thermal efficiency of four-stroke engine is more due to positive scavenging: This is incorrect. Thermal efficiency refers to the conversion of heat from combustion into usable work. Four-stroke engines rely on negative scavenging, where fresh air pushes out exhaust gases, while two-stroke engines use positive scavenging, where the incoming fuel mixture displaces exhaust gases. While both have their advantages and disadvantages, neither directly contributes to improved thermal efficiency.
Which of the following is not an internal combustion engine?
Two-stroke petrol engine
Four-stroke petrol engine
Diesel engine
Steam Turbine
The answer is Steam Turbine.
All the other options are types of internal combustion engines. They operate by burning fuel within a cylinder, creating heat and pressure that drive pistons and generate mechanical power.
A steam turbine, on the other hand, is an external combustion engine. It doesn't burn fuel within itself but instead uses externally generated steam to drive turbine blades and create power. The heat source for the steam can be various, including burning fossil fuels, nuclear energy, or solar power.
The thermodynamic cycle on which the petrol engine works is:
Otto cycle
Joule cycle
Rankine cycle
Stirling cycle
The petrol engine, also known as a spark-ignition engine, operates on the Otto cycle.
The Otto cycle describes four distinct processes:
Isochoric compression (constant volume): The air-fuel mixture is compressed within the cylinder by the rising piston.
Isobaric heat addition (constant pressure): The spark plug ignites the compressed mixture, causing a rapid increase in temperature and pressure.
Isentropic expansion (constant entropy): The hot, expanding gases push the piston down, generating power.
Isochoric heat rejection (constant volume): The exhaust valve opens, and the waste heat is expelled through the cylinder.
Which is the third port, apart from exhaust and suction ports used in two-stroke engine?
Transfer port
Transport valve
Top dead centre
Bottom dead centre
You're correct, the Transfer port is indeed the third port in a two-stroke engine, alongside the exhaust and suction ports.
The transfer port stands as the clear answer as the third crucial port in a two-stroke engine's operation.
A two-stroke engine gives ________ mechanical efficiency than a four-stroke cycle engine.
Lower
Equal
None of the mentioned
A two-stroke engine generally has lower mechanical efficiency than a four-stroke engine.
While two-strokes offer advantages like lighter weight and simpler design, their lower efficiency translates to higher fuel consumption and lower power output compared to four-stroke engines for the same displacement.
Therefore, the correct answer is Lower.
Number of working strokes per minute for a two-stroke cycle engine is _________ the speed of the engine in RPM.
Equal to
One-half
Twice
Four-times
The number of working strokes per minute for a two-stroke cycle engine is twice the speed of the engine in RPM.
for a two-stroke engine running at N RPM, the number of working strokes per minute would be:
Working strokes/minute = 2 * Engine speed (RPM) = 2 * N
So, the number of working strokes is directly proportional to the engine speed and is always twice the RPM value.
Therefore, the correct answer is Twice.
In a four-stroke cycle, the minimum temperature inside the engine cylinder occurs at the
Beginning of suction stroke
End of suction stroke
Beginning of exhaust stroke
End of exhaust stroke
In a four-stroke cycle, the minimum temperature inside the engine cylinder occurs at the beginning of suction stroke.
Suction stroke: During this stroke, the piston moves downward, drawing in a fresh air-fuel mixture through the open intake valve. This air-fuel mixture is typically at ambient temperature, which is usually lower than the residual hot gases remaining from the previous cycle.
considering the temperature changes throughout the cycle, the coolest point is just before the fresh air-fuel mixture enters, which occurs at the beginning of the suction stroke
The air standard Otto cycle consists of
Two constant volume and two isentropic processes
Two constant pressure and two isentropic processes
Two constant pressure and two constant volume processes
None of the above
The correct answer is: Two isentropic and two constant volume processes.
The Otto cycle describes the ideal operation of a spark-ignition engine, consisting of four distinct processe.
the air standard Otto cycle involves two isentropic processes (compression and expansion) and two constant volume processes (heat addition and rejection).
What is the purpose of the crankshaft in an internal combustion engine?
To control the valve timing
To convert linear motion to rotary motion
To compress the air-fuel mixture
To regulate the fuel injection
Out of the options you provided, the main purpose of the crankshaft in an internal combustion engine is To convert linear motion to rotary motion.
the key function of the crankshaft is to transform the up-and-down (linear) movement of the pistons into the continuous rotational motion (rotary) that ultimately drives the wheels or other devices connected to the engine. It achieves this by being connected to the pistons through connecting rods that convert the linear motion into turning the crankshaft around its axis.
So, the correct answer is To convert linear motion to rotary motion.