Steam Boilers_ Engines_ Nozzles And Turbines — Part 1 MCQs with Explanations

Mechanical draught refers to the artificial method of supplying air and removing flue gases using fans in a boiler system. Smoke formation occurs due to incomplete combustion of fuel, which indicates insufficient air supply. When the amount of smoke increases , it means combustion is poor and more air is required to burn the fuel completely. To overcome this, the mechanical draught is increased so that more air is supplied to the furnace, improving combustion and reducing smoke. Hence, mechanical draught increases with the amount of smoke .

Clearance in the engine cylinder is the volume left between the piston and the cylinder head when the piston is at top dead center. This clearance is essential for mechanical reasons, such as preventing contact between piston and valves. But increasing this clearance leads to: ✔ Lower Compression Ratio: More clearance means less compression, reducing engine power and efficiency. ✘ Mean Effective Pressure (MEP) does not increase: In fact, it decreases because the combustion gases expand over a larger volume with less pressure buildup. ✘ Work Done does not increase: With a lower pressure due to lower compression, the work output also drops. ✔ Overall, efficiency drops as more heat is wasted and less useful work is obtained. Thus, only Option C is correct. Options A and B are incorrect, so D (All of these) is wrong.

The natural draught mainly depends upon the height of the chimney.

Rankine cycle is the correct answer to “The expansion of steam in a nozzle follows”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Steam enters at one end and exhausts at the centre is the correct answer to “In a uniflow engine”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Fouling of heat transfer surfaces is the correct answer to “Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Fusible plug is the correct answer to “A _________ in a boiler is used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit.”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

One is the correct answer to “The radius of a dished head is taken approximately as”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

All of the above is the correct answer to “Boiler parameters are expressed by”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

180° to each other is the correct answer to “The high pressure and low pressure cylinders in a Woolf type compound engine are regarded as having cranks”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

0° to each other is the correct answer to “The high pressure and low pressure cylinders in a Tandem type compound engine are regarded as having cranks”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

90° to each other is the correct answer to “The high pressure and low pressure cylinders in a receiver type compound engine are regarded as having cranks”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

20 atmospheres is the correct answer to “In a steam engine, superheated steam from the boiler is fed into the steam chest at a pressure of”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

All of these is the correct answer to “The draught may be produced by a”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

225.6 kg/cm2 is the correct answer to “At which pressure the properties of water and steam become identical”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

250 bar is the correct answer to “The average operating pressure of Benson boiler is”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

135 tonnes/h is the correct answer to “The rate of steam produced in Benson boiler is”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

All of the above is the correct answer to “The effect of bleeding is that”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Economiser is the correct answer to “Which of the following is not a boiler mounting”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Less than is the correct answer to “The pressure of steam in the engine cylinder at the beginning of the stroke is ________ the boiler pressure.”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Complete account of heat supplied by 1 kg of dry fuel and the heat consumed is the correct answer to “The heat balance sheet for the boiler shows the”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Coal gas is the correct answer to “Which of the following gases has the highest calorific value”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Forced circulation type is the correct answer to “Which type of boiler can meet rapid changes of load”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Locomotive boiler is the correct answer to “Which of the following boiler is best suited to meet the fluctuating demand of steam”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

When the cross-section of the nozzle increases continuously from entrance to exit is the correct answer to “A nozzle is said to be a divergent nozzle”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

All of these is the correct answer to “The compounding of turbines is done in order to”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

To convert rotary motion of the crankshaft into to and fro motion of the valve rod is the correct answer to “The function of an eccentric rod is”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

2.86 is the correct answer to “A double acting steam engine with a cylinder diameter of 190 mm and a stroke of 300 mm has a cut-off of 0.35. The expansion ratio for this engine is nearly”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Can be raised rapidly is the correct answer to “Steam in water tube boiler as compared to fire tube boiler”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Isentropic is the correct answer to “Thermal equilibrium means that the flow of steam is”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

218 kg/cm2 abs and 373°C is the correct answer to “A supercritical boiler is one that operates above the pressure and temperature of following values”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

To circulate water is the correct answer to “In forced circulation steam boilers, the force is applied”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Better burning is the correct answer to “Pulverized fuel is used for”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

All of these is the correct answer to “The fittings mounted on the boiler for its proper and safe functioning is a”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Decreases is the correct answer to “The relative heat absorption for successively added equal areas of boiler convection heating surfaces”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Less is the correct answer to “The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine.”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

$${\text{I}}{\text{.P}}{\text{.}}$$ is the correct answer to “Willian's law states that the steam consumption per hour provided with a throttled governor is proportional to (where $${\text{I}}{\text{.P}}{\text{.}}$$ = Indicated Power)”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Diagram efficiency is the correct answer to “Blading efficiency is also known as”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

Gross efficiency is the correct answer to “Stage efficiency is also known as”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.

The proximate analysis is the correct answer to “The behavior of coal in a furnace is determined by”. This question is standard in competitive examination syllabi for Steam Boilers_ Engines_ Nozzles And Turbines.