CAE Vehicle Dynamics & Powertrain

Question 1

What is the Otto cycle in internal combustion engines?

Accepted Answer

A four-stroke thermodynamic cycle (intake, compression, power, exhaust) used in spark-ignition engines

Answer

The Otto cycle describes the idealized thermodynamic process in gasoline engines: intake of air-fuel mixture, compression, combustion/power stroke, and exhaust of burned gases.

Question 2

What is the purpose of a catalytic converter in a vehicle's exhaust system?

Accepted Answer

To chemically convert harmful pollutants (CO, HC, NOx) into less harmful emissions (CO2, H2O, N2)

Answer

Catalytic converters use precious metal catalysts (platinum, palladium, rhodium) to facilitate chemical reactions that convert carbon monoxide, hydrocarbons, and nitrogen oxides into less harmful substances.

Question 3

What does the term 'torque' mean in automotive engineering?

Accepted Answer

A rotational force measured in pound-feet or Newton-meters that indicates an engine's ability to do work

Answer

Torque is the twisting force produced by an engine's crankshaft. Higher torque at lower RPMs provides better acceleration and pulling power, which is why it's critical for towing and performance.

Question 4

What is regenerative braking in hybrid and electric vehicles?

Accepted Answer

A system that converts kinetic energy during braking back into electrical energy stored in the battery

Answer

Regenerative braking uses the electric motor as a generator during deceleration, converting kinetic energy into electrical energy that recharges the battery, improving overall vehicle efficiency.

Question 5

What is the function of a differential in a vehicle drivetrain?

Accepted Answer

To allow the drive wheels to rotate at different speeds during turns while transmitting power from the driveshaft

Answer

During turns, the outer wheel travels a greater distance than the inner wheel. The differential allows this speed difference while evenly distributing engine torque to both drive wheels.

(CAE) Certified Automotive Engineer Practice Test

(CAE) Certified Automotive Engineer Practice Test

CAE Vehicle Dynamics & Powertrain