1.
An average man can develop the maximum power of about?
Correct Answer
A. 0.1 Hp
Explanation
An average man can develop a maximum power of about 0.1 Hp. This means that an average man can generate approximately 0.1 horsepower of energy.
2.
In a four-stroke cycle engine for best results stroke bore ratio should be equal to?
Correct Answer
C. 1.50
Explanation
In a four-stroke cycle engine, the stroke bore ratio refers to the ratio between the length of the piston stroke and the diameter of the cylinder bore. The stroke bore ratio affects the engine's efficiency and performance. A ratio of 1.50 is considered to be ideal for achieving the best results. This ratio ensures optimal combustion and allows for efficient intake and exhaust flow. It strikes a balance between power output and engine size, resulting in improved fuel efficiency and overall performance.
3.
Thermal efficiency of a diesel engine varies between:
Correct Answer
C. 32 – 35%
Explanation
The correct answer is 32 - 35%. This range represents the typical thermal efficiency of a diesel engine. Thermal efficiency is a measure of how effectively an engine converts heat energy from fuel into useful work. Diesel engines are known for their high thermal efficiency compared to other types of engines. The given range falls within the typical efficiency range for diesel engines, indicating that they can convert 32 - 35% of the heat energy from fuel into useful work.
4.
The compression ratio of diesel engine is?
Correct Answer
C. 14 – 20:1
Explanation
The compression ratio of a diesel engine refers to the ratio of the volume of the cylinder when the piston is at the bottom of its stroke to the volume when the piston is at the top of its stroke. A higher compression ratio leads to greater efficiency and power output. The range of 14-20:1 indicates that the volume at the top of the stroke is 14-20 times smaller than the volume at the bottom of the stroke, which is a common range for diesel engines.
5.
The specific fuel consumption of diesel engine is?
Correct Answer
B. 200 g/bhp-h
Explanation
The specific fuel consumption of a diesel engine is typically measured in grams per brake horsepower-hour (g/bhp-h). The correct answer, 200 g/bhp-h, suggests that a diesel engine consumes 200 grams of fuel per hour for every unit of brake horsepower it produces. This measurement is used to evaluate the efficiency of a diesel engine, with lower values indicating better fuel efficiency.
6.
The calorific value of high speed diesel is?
Correct Answer
B. 10500 kcal/kg
Explanation
The calorific value of high speed diesel is 10500 kcal/kg. Calorific value refers to the amount of heat energy released when a fuel is burned completely. In the case of high speed diesel, it has a calorific value of 10500 kcal/kg, meaning that for every kilogram of high speed diesel burned, it releases 10500 kilocalories of heat energy.
7.
In a four-stroke diesel engine, the sequence of strokes is?
Correct Answer
A. Intake, Compression, Expansion and Exhaust
Explanation
In a four-stroke diesel engine, the sequence of strokes is intake, compression, expansion, and exhaust. This is the correct order of events that occur during each cycle of the engine. During the intake stroke, the piston moves downward, allowing air to enter the cylinder. In the compression stroke, the piston moves upward, compressing the air. The expansion stroke is when fuel is injected into the compressed air, causing it to ignite and expand, pushing the piston downward. Finally, in the exhaust stroke, the piston moves upward, pushing the burnt gases out of the cylinder.
8.
The clearance between the rocker arm and the valve stem is called?
Correct Answer
C. Tappet clearance
Explanation
The clearance between the rocker arm and the valve stem is known as tappet clearance. Tappet clearance refers to the space or gap that exists between the tappet (also known as a lifter) and the valve stem in an internal combustion engine. This clearance is important for proper functioning of the valve mechanism, as it allows for expansion and contraction of the components due to heat. Adjusting the tappet clearance ensures that the valve opens and closes at the correct time, optimizing engine performance and preventing damage.
9.
In a four-stroke cycle engine, the speed of the cam shaft should be?
Correct Answer
B. Half the speed of crank shaft
Explanation
In a four-stroke cycle engine, the cam shaft should rotate at half the speed of the crank shaft. This is because the cam shaft is responsible for operating the intake and exhaust valves, which need to open and close once for every two revolutions of the crank shaft. Therefore, if the cam shaft rotated at the same speed as the crank shaft, the valves would not open and close at the correct intervals, leading to improper engine function.
10.
The dimensions of kinematic viscosity are?
Correct Answer
C. M0L2T-1
Explanation
The dimensions of kinematic viscosity are M0L2T-1. This is because kinematic viscosity is defined as the ratio of dynamic viscosity (M0L-1T-1) to density (M0L-3), resulting in the dimensions M0L2T-1.
11.
In a spark-ignition engine, the intake valve opens about 10 degrees.
Correct Answer
A. Before TDC
Explanation
In a spark-ignition engine, the intake valve opens before the piston reaches the top dead center (TDC) position. This allows the air-fuel mixture to enter the combustion chamber before the piston starts its downward stroke. Opening the valve before TDC ensures efficient filling of the cylinder with the mixture, maximizing the engine's power output.
12.
The average firing interval for six-cylinder, four-cycle engine is:
Correct Answer
A. 120°
Explanation
The average firing interval for a six-cylinder, four-cycle engine is 120°. This means that each cylinder fires every 120° of crankshaft rotation. In a four-cycle engine, each cylinder goes through four strokes: intake, compression, power, and exhaust. The firing interval refers to the time between each power stroke of the cylinders. In a six-cylinder engine, the firing order is typically designed to evenly distribute the firing intervals, resulting in a firing interval of 120°.
13.
The main difference between flywheel and governor is:
Correct Answer
C. Flywheel stores energy and governor controls speed
Explanation
The correct answer is "Flywheel stores energy and governor controls speed." A flywheel is a heavy rotating disc that stores kinetic energy and helps to maintain a steady rotational speed in a machine. On the other hand, a governor is a device that regulates the speed of an engine or machine by controlling the fuel or power supply. While a flywheel is fixed to the crankshaft, a governor is not directly connected to the crankshaft. Therefore, all the given statements are true and correctly differentiate between a flywheel and a governor.
14.
In IC engines the turbocharger is driven by?
Correct Answer
B. Exhaust gas
Explanation
In IC engines, the turbocharger is driven by exhaust gas. A turbocharger is a device that increases the air intake into the engine, resulting in improved combustion and increased power output. It works by using the energy from the exhaust gases to drive a turbine, which in turn drives a compressor that forces more air into the engine. This process is known as forced induction and helps to enhance the engine's performance. Therefore, the correct answer is exhaust gas.
15.
Swinging type of drawbar in tractor advantageous because of it?
Correct Answer
D. All of the above
Explanation
The swinging type of drawbar in a tractor is advantageous because it reduces side draft, helps in taking short turns with a machine wider than the tractor, and leaves only a small area uncovered at the corners of the field. This means that it provides multiple benefits, making it the most suitable option among the given choices.