Heat Engines Set 15 MCQs

Q1 | Change in internal energy is least during

25 to 30

Constant pressure process

Constant volume process

Adiabatic process

Isothermal process

Q2 | Which of the following is not a petroleum product?

Methylated spirit

Lubricating oil

Kerosene

Carbon dioxide

Petrol

Q3 | Thermal efficiency of a standard Otto cycle for a compression ratio 5.5, will be

100%

47.50%

20%

35.40%

50%

Q4 | The calorific value of methane can be determined by

Bomb calorimeter

Bunsen's calorimeter

Orsat's apparatus

Exhaust gas calorimeter

None of the above

Q5 | The fact that the product of pressure and volume of a fixed amount of gas is approximately a constant value is known as

Charle's law

Gay Lusac's law

Dalton's law

Lewis law

None of the above

Q6 | Air fuel ratio for a jet engine is of the order of

60;1

15;1

600;1

20;1

10;1

Q7 | A steam nozzle is said to be choked when

Pressure at throat is equal to steam supply pressure

Throat gets clogged

Flow is at maximum value of critical exit pressure

Steam flow through nozzle ceases

Pressure at throat is less than the exit pressure

Q8 | In a four stroke cycle the minimum temperature inside the engine cylinder occurs

At the end of exhaust stroke

At the end of suction stroke

At the end of compression stroke

At the beginning of exhaust stroke

At the beginning of suction stroke

Q9 | According to Charle's law

At constant pressure the volume of a gas is proportional to its absolute temperature

At constant temperature, pressure is proportional to temperature

At constant temperature, pressure of a gas is proportional to its volume

At constant volume the absolute pressure is proportional to the temperature

None of the above

Q10 | Prony brakes are used for testing

Slow speed engines

High speed engines

Engines with small flywheel

Small engines

Large capacity engines

Q11 | In wet dry lubrication of diesel engines

Oil is splashed

Oil is splashed and pumped to various points

Oil is pumped to various points

All of the above

None of the above

Q12 | In a velocity compounded impulse turbine, while steam flows through the second row of moving blades

The velocity increases

The velocity reduces

Both velocity as well as pressure increase

The velocity remains constant

The pressure remains constant

Q13 | Ignition accelerators are often used for

Diesel engine fuels

Petrol engine fuels

Gas turbine fuels

Gas generators

All of the above

Q14 | Which one of the following statements is incorrect

Combustion is the processes of heat liberation

Combustion is a chemical reaction

Combustion is rapid oxidation

All of the above

None of the above

Q15 | During idling in a compression ignition engine the air fuel ratio may be of the order of

5

20

10

15

30

Q16 | Solid injection in diesel engines implies

Use of solid fuels

Supply of fuel in the form of solid

Injecting fuel with lubricating oil

Injecting fuel and air simultaneously

Injecting fuel without air

Q17 | Which fuel has maximum resistance to detonation

Alcohol

n-Heptane

Toulene

Iso-octane

Benzene

Q18 | The level of oil in engine cylinder should be checked when the engine is

Not running

Running

During starting

During cranking

None of the above

Q19 | The molecular weight of a mixture containing 20% oxygen, 20 percent nitrogen and 60 percent carbon dioxise on volume bases will be nearly

38.4

Carbon dioxide

41.4

29.9

33.3

Q20 | Dissociation is

Process of heat liberation in which no flame exist

Same is combustion

Combustion without heat

Slow combustion

Smokeless combustion

Q21 | Thermodynamic processes are those

Where a difference is observed in any macroscopic property of the system between different times or state

Where a difference is observed in any microscopic property of the system between different times or state

Which occurs in the direction of an intensive property or driving force contained within the system

Which require an agency outside the system to force the process

None of the above

Q22 | A Lungistrom turbine is a

Radial flow reaction turbine

Axial flow reaction turbine

Radial flow impulse turbine

Mixed flow impulse turbine

None of the above

Q23 | Highest useful compression ratio is the compression ratio at which

An engine can be safely operated

An engine gives maximum thermal efficiency

An engine operates smoothly

Detonation first becomes audible

None of the above

Q24 | The pour point of diesel fuel oil must be

More than the coldest atmospheric temperature at which oil is to be pumped

Less than 0?C

Less than the coldest atmospheric temperature of which oil is to be pumped

More than 100?C

More than 0?C

Q25 | The emission of carbon monoxide in automobile exhaust will be low when the vehicle is

Cruising at low speeds

Idling

Decelerating

Cruising at high speeds

Accelerating