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This set of Heat Engines Multiple Choice Questions & Answers (MCQs) focuses on Heat Engines Set 9
Q1 | A radiation pyrometer is used for temperatures
- Upto 100?C
- Below 100?C
- Above 500?C
- 250 - 500?C
- 100 - 250?C
Q2 | The processes in a Rankine cycle are
- Two isothermal and two isentropic
- Two isothermal and two polytropic
- Two isothermal and two isobaric
- One constant pressure, one constant volume and two polytropic
- None of the above
Q3 | The function of a receiver in compressor installations is
- To collect compressed air
- To dempen pulsations or pressure waves incompressor discharge
- To reduce temperature of compressed air
- To reduce moisture content of compressed air
- None of the above
Q4 | In an analysis report of a sample of coal, the percentage of one of the constituents is specified as 2.5%. This constituent could be
- Carbon steel
- Ash
- Moisture
- Sulphur
- None of the above
Q5 | Apart from reducing friction and cooling the surfaces, the function of lubricant in I.C. engines is
- To improve thermal efficiency
- To clean the surfaces by carrying away the carbon and metal particles cansed by wear
- To reduce noise
- To reduce vibrations
- None of the above
Q6 | During throttle governing of steam engines
- Cut off of the engine cylinder changes according to the load
- Pressure of steam supplied does not change with the load
- Thermal efficiency of the engine reduces
- Mechanical efficiency of the engine increases
- None of the above
Q7 | The efficiency of jet engine is higher at
- Lower altitudes
- Higher altitude
- Low speeds
- High speeds
- None of the above
Q8 | In a compression ignition engine the fuel consumption will increase if the back (exhaust) pressure is
- Decreased
- Increased
- Does not have any effect
- Depends on other factors
- None of the above
Q9 | If petrol is supplied to a diesel engine
- The engine will run at high speeds
- The engine will run with excessive vibrations
- The engine will explode
- The engine will run with high knocking
- The engine will not run
Q10 | A sample of water having pH value of 7 is
- Acidic
- Alkaline
- Neutral
- None of the above
Q11 | Which of the following has the lowest pressure in a petrol engine?
- Gases during power stroke
- Mixture at the end of compression stroke
- Mixture at the beginning of suction stroke
- Mixture at the end of suction stroke
- Gases during exhaust stroke
Q12 | The discharge of hydrocarbons from an automobile exhaust is minimum when the vehicle is
- Decelerating
- Cruising at high speeds
- Cruising at low speeds
- Accelerating
- Idling
Q13 | Load curve is the plot of
- Load versus generatng capacity
- Load versus current
- Load versus time
- Load versus cost of power
- None of the above
Q14 | With reference to a safety valve the blow down pressure is the pressure at which
- Valve opens
- Valve closes after opening
- Valve opens initially
- Valve spring pressure is adjusted
- None of the above
Q15 | A four wheel drive automobile has
- Four stroke engine
- Air cooled engine
- Four flywheels
- Four cylinders
- Two differentials
Q16 | The work done in compressing 1 kg of air in compression will be least when the value of index is
- 1.1
- 1
- 1.2
- 1.41
- 1.5
Q17 | Separators are generally used in air compressor installations
- Between after cooler and receiver
- Before first stage suction
- Before intercooler
- After intercooler
- None of the above
Q18 | For the same maximum pressure and heat input, the most efficient cycle is
- Diesel
- 5 to 10 percent
- Brayton
- Otto
- Dual
Q19 | In compression ignition engines swirl is
- Circular motion imparted to gases after combustion
- Circular motion imparted to suction air
- Radial motion imparted to fuel air mixture
- Directional movement of fuel spray
- None of the above
Q20 | Which of the following acts as a step up transformer in the ignition circuit of a petrol engine?
- Battery
- Coil
- Plug
- Distributor
- Magneto
Q21 | Tidal power is the power generated from
- Raw sea water
- Waves of the ocean
- Rise and fall tides
- Thermal energy of ocean water
- Chemicals in sea water
Q22 | Percentage improvement in power in case of a four stroke diesel engine with the help of a supercharger may be expected in the range
- 25
- 35
- 75
- 50
- 100
Q23 | Thermal efficiency of a spark ignition engine at full load usually is in the range
- 30 to 35 percent
- 50 to 70 percent
- 70 to 90 percent
- 10 to 25 percent
- 5 to 10 percent
Q24 | A Lungistrom turbine is
- Impulse turbine
- Reaction turbine
- Outward radial flow turbine
- Inward flow impulse reaction turbine
- None of the above
Q25 | Diesel engine has air fuel ratio of 30 ; 1 during idling. A petrol engine can also work on such mixture provided
- Ignition timing is changed
- Carburettor is modified
- Dannot run as it is impossible
- Runs smoothly at lower speeds only
- Engine is suitably modified