WorksheetsQuiz on Internal Combustion Engines
Total questions: 25
Worksheet time: 13mins
In an air-standard cycle analysis, the working fluid is assumed to be:
Air as an ideal gas with variable specific heats
Air as an ideal gas with constant specific heats
Steam with constant pressure
Perfect gas with humidity
Which cycle has the highest efficiency for the same maximum and minimum temperatures?
Otto cycle
Diesel cycle
Carnot cycle
Brayton cycle
The efficiency of the Otto cycle depends on:
Pressure ratio
Cut-off ratio
Compression ratio
Expansion ratio
In the Diesel cycle, the efficiency increases if the cut-off ratio is:
Increased
Decreased
Equal to compression ratio
Equal to unity
The heat addition process in an ideal Diesel cycle occurs at:
Constant volume
Constant pressure
Constant temperature
Variable pressure
An engine where combustion takes place inside the cylinder is called:
External combustion engine
Internal combustion engine
Reciprocating steam engine
Stirling engine
Which of the following is a spark ignition engine?
Diesel engine
Petrol engine
Gas turbine
Steam engine
The function of the cylinder in an IC engine is to:
Convert reciprocating motion to rotary motion
Provide space for fuel storage
Provide a combustion chamber and guide the piston
Supply air-fuel mixture
The material commonly used for pistons in automotive IC engines is:
Cast iron
Forged steel
Aluminium alloy
Brass
The crankshaft is supported in the crankcase by:
Cylinder liners
Bearings
Valve seats
Piston rings
The wrist pin connects:
Crankshaft to flywheel
Piston to connecting rod
Connecting rod to crankshaft
Camshaft to push rod
The inlet valve in a four-stroke petrol engine generally opens:
At TDC
Before TDC
After BDC
At BDC
In a four-stroke cycle, the number of power strokes per revolution of the crankshaft is:
1
0.5
2
4
In a two-stroke engine, one power stroke occurs every:
One crankshaft revolution
Two crankshaft revolutions
Half crankshaft revolution
Four crankshaft revolutions
Compared to a four-stroke engine, a two-stroke engine generally has:
Higher fuel efficiency
More power for the same engine size
Lower lubrication requirement
Lower wear and tear
In S.I. engines, the air-fuel mixture is ignited by:
Heat of compression
Spark plug
Glow plug
Self-ignition temperature
In C.I. engines, the fuel is ignited by:
Spark plug
Glow plug
Heat generated during compression
Electric heater
The valve timing diagram shows:
Sequence of ignition events
Opening and closing of valves relative to piston position
Fuel injection pressure variation
Engine cooling sequence
The cut-off ratio in Diesel cycle is the ratio of:
Cylinder volume before combustion to after combustion
Cylinder volume at end of heat addition to volume at start of heat addition
Compression volume to clearance volume
Volume at intake valve opening to volume at exhaust valve opening
The T-S diagram for the Otto cycle has heat addition at:
Vertical line
Horizontal line
Inclined line
Curved line
Which of the following is an advantage of a four-stroke engine over a two-stroke engine?
Higher specific power output
Lower fuel consumption per kWh
Lighter construction
Simpler lubrication system
The crank pin is the part of the crankshaft to which the:
Flywheel is attached
Big end of connecting rod is attached
Crankcase is connected
Timing gear is fixed
Which material is commonly used for inlet and exhaust valves?
Mild steel
Aluminium alloy
Nickel-chromium steel
Cast iron
In a port timing diagram, ports are generally used in:
Four-stroke SI engines
Two-stroke engines
Four-stroke CI engines
Steam turbines
The efficiency of an Otto cycle is given by:
1-1/rγ-1
1-1/rγ
1-γ/r
1-1/γr
