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WorksheetsIntro to Automobiles Quiz-2
Total questions: 60
Worksheet time: 3600secs
Which of the following is a key difference between a turbocharger and a supercharger?
Turbochargers operate only at high RPM
Superchargers use exhaust gases for energy
Superchargers are crankshaft-driven; turbochargers are exhaust-driven
Turbochargers reduce engine compression
What is the primary advantage of a twin-scroll turbocharger over a single-scroll design?
. Increases engine friction
Minimizes exhaust pulse interference and improves low-RPM response
Reduces thermal efficiency
Requires dual intercoolers
Which of the following is a disadvantage of a roots-type supercharger?
Delayed throttle response
Requires exhaust energy
Needs intercooling always
Less efficient at high RPMs
Which type of supercharger is most efficient at high RPMs and speeds?
Roots
Centrifugal
Twin-screw
Positive displacement
What is the role of a variable geometry turbocharger (VGT)?
To reduce fuel injection timing
To adjust turbine blade angle for optimal airflow
To reduce valve overlap
To separate intake and exhaust cycles
Sequential twin-turbo systems are designed to...
Use one turbo for intake and one for exhaust
Run turbos in series to generate high boost at all RPMs
Reduce the number of catalytic converters
Replace superchargers in large engines
What is the purpose of an intercooler in a forced induction engine?
Increase exhaust backpressure
Reduce the temperature of compressed air
Prevent detonation by cooling coolant
Lower oil viscosity
Anti-lag systems are primarily used in:
Drag racing vehicles
Rally cars with turbochargers
Naturally aspirated engines
Diesel locomotives
Which of the following is a common side effect of an anti-lag system?
Reduced boost pressure
Excessive engine knocking
High exhaust temperature and turbo wear
Delayed throttle response
Boost pressure is defined as:
Pressure in the crankcase
Total cylinder pressure during ignition
Intake manifold pressure above atmospheric level
Absolute pressure at sea level
What prevents a turbocharged engine from overboosting?
Fuel injector
Wastegate
Throttle plate
Crank sensor
What is the function of a blow-off valve in a turbocharged petrol engine?
To increase exhaust gas recirculation
To inject extra fuel during boost
To release pressurized air when the throttle closes
To bypass the wastegate
Turbo lag is caused by:
Delayed ignition
Friction in the pistons
Time taken for exhaust gases to spool the turbine
Valve overlap
Which parameter must be carefully managed to avoid detonation in a boosted engine?
Exhaust flow
Intake temperature
Valve lift
Crank angle sensor
Why is a lower static compression ratio often used in turbocharged engines?
To increase fuel economy
To allow higher RPM operation
To prevent knock at high boost
To reduce oil consumption
What is the effect of direct fuel injection in a forced induction system?
Cools intake charge and suppresses knock
Reduces turbo lag
Increases frictional losses
Eliminates the need for intercooling
Which of the following is true about volumetric efficiency in a forced induction engine?
It is always lower than 100%
It remains constant regardless of engine speed
It can exceed 100%
It decreases with boost pressure
What does a compressor map help engineers determine?
Fuel injector size
Best air-fuel ratio
Optimal operating zone of the turbo
Cylinder wall thickness
What does a compressor map help engineers determine?
Turbo fails to spool
Air reverses through the compressor due to low demand
Oil pressure drops
Boost pressure drops below vacuum
Why are twin-turbo setups sometimes preferred over single large turbos?
They are cheaper
They reduce fuel consumption
They balance low-end response and high-end power
They eliminate the need for a wastegate
In a twin-scroll turbocharger, the divided scroll is used to minimize ________ __________.
(a)
At high altitudes, forced induction engine efficiency can be improved by increasing ________ __________.
(a)
In an engine with forced combustion, detonation can be controlled by using ________ ________ ________.
(a)
In a turbocharged petrol engine, a diverter valve redirects compressed air back into the intake during ________ ________.
(a)
A lower static compression ratio is used in turbocharged engines to prevent ________ under ________.
(a)
Direct injection benefits forced combustion systems by cooling the intake air through ________ ________ ________ in the cylinder.
(a)
A boost controller regulates ________ ________ to control boost pressure in a turbocharged system.
(a)
Which sensor is most directly responsible for adjusting ignition timing in response to engine knock?
Crankshaft position sensor
Knock sensor
O2 sensor
MAP sensor
Intercoolers in turbocharged engines are used to cool compressed air and increase its (a) .
Which of the following sensors is responsible for synchronizing the fuel injector pulses with the intake valve timing?
Crankshaft position sensor
Throttle position sensor
Camshaft position sensor
MAF sensor
Forced induction significantly increases an engine’s ________ ________ beyond 100%.
(a)
A failing Throttle Position Sensor (TPS) sensor may cause which of the following symptoms?
Delayed transmission shifts
Overheating
Oil pressure drop
Misfire in high RPM
Engine knock in a forced induction engine is primarily caused by ________ of ________ due to high temperatures.
(a)
The IAT sensor helps the ECU to:
Adjust spark timing during high loads
Compensate fuel mixture based on air temperature
Activate the EGR valve
Adjust oil pressure for turbo systems
A wastegate diverts excess exhaust gases to regulate ________ ________ in a turbocharged engine.
(a)
What type of signal does the oxygen sensor (O₂) typically produce in a narrowband system?
0-5V linear
Frequency modulated
0-1V switch-type signal
PWM signal
Using a ________ ________ ________ is NOT a method to mitigate turbo lag.
(a)
A NOx sensor in a diesel vehicle is primarily used to:
Detect unburned hydrocarbons
Monitor particulate matter
Measure nitrogen oxides in exhaust gases
Detect ethanol content in fuel
In forced induction systems, boost pressure is defined as the ________ ________ above ________ pressure.
(a)
Which sensor provides real-time feedback to prevent engine overheating due to low oil lubrication?
Fuel pressure sensor
Oil pressure sensor
EGT sensor
Knock sensor
Flat-plane V8 engines used in high-performance cars are known for their __________ throttle response and __________ crankshaft.
(a)
The ________ ________ protects the engine from overboost conditions by releasing excess intake pressure.
(a)
Compressor surge occurs when the (a) reverses due to low demand, often during sudden throttle closure.
The primary thermodynamic benefit of forced induction is a ________ ________ ________ output.
(a)
A faulty fuel pressure sensor may result in:
Incorrect spark plug firing
Erratic turbo boost levels
Hard starts or stalling due to incorrect fuel delivery
Oil leakage at the intake manifold
In diesel engines, forced combustion helps by increasing the ________ of ________ for better combustion.
(a)
The crankshaft position sensor helps the ECU determine:
Exact throttle position for acceleration
Timing of ignition spark relative to piston position
Air-fuel ratio
Mass flow of intake air
(a) sensors are responsible for adjusting ignition timing in response to engine knock.
Which of the following sensors directly affects the air-fuel mixture and emissions by analyzing combustion results?
Oil temperature sensor
Camshaft position sensor
Oxygen (O₂) sensor
IAT sensor
Cross-plane V8 engines typically require a more complex exhaust system due to (a) firing pulses between cylinder banks.
The onset of knock in a turbocharged engine is primarily governed by which of the following?
Cylinder pressure
Cylinder temperature
Intake air humidity
Exhaust gas temperature
Which of the following describe the working principle of a vane air flow meter (AFM)?
Thermoelectric expansion
Change in magnetic reluctance
Pressure vs volume calibration
Mechanical flap deflection by airflow
Where is the Exhaust Gas Temperature (EGT) sensor typically located in turbocharged engines?
Inside the throttle body
Before the catalytic converter
Before the turbocharger
In the crankcase
Compressor efficiency in a forced induction system is defined as the ratio of which of the following?
Isentropic work
Heat rejection
Actual work
Boost pressure
Which of the following are effects of forced induction on the torque curve across a wider RPM range?
Reduces engine displacement
Flattens the torque curve
Boosts the torque curve
Narrows the powerband
Which of the following are characteristics of flat-plane V8 engines used in high-performance cars?
High torque at low RPM
Strong low-end vibration damping
Faster throttle response
Lighter crankshaft
What is a primary difference between a MAF sensor and a MAP sensor?
MAF measures vacuum; MAP measures air volume
MAF uses a diaphragm; MAP uses a hot wire
MAF directly measures air mass; MAP estimates air mass based on pressure
MAP uses oxygen levels; MAF uses fuel pressure
Which sensor's failure is most likely to cause poor cold starts due to incorrect fuel-air mixture adjustments?
Knock sensor
Fuel temperature sensor
NOx sensor
Coolant temperature sensor
A failing oil temperature sensor could lead to:
Rich fuel mixture during warmup
Poor ignition timing
Improper lubrication system behavior under high load
Lean mixture under boost
What is the primary reason flat-plane V8 engines can typically rev higher than cross-plane V8s?
Use of smaller displacement cylinders
Better crankshaft balance at low RPM
Lower rotating mass and more uniform firing order
Use of turbocharging in flat-plane setups
