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Sample Practice Test Questions
Just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. This describes which engine stroke?
power
During the power stroke, just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. The resulting expansion due to combustion pushes the piston back down the cylinder toward bottom dead center.
The coldest point in the Earth's atmosphere is reached in which atmospheric layer?
mesosphere
In the mesosphere, temperature again drops as altitude increases until the coldest point in the Earth's atmosphere, the mesopause, is reached where temperatures fall to −225 °F (−143 °C).
If a = 4, b = 2, c = 9, and d = 4, what is the perimeter of this quadrilateral?
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 4 + 2 + 9 + 4
p = 19
An object's resistance to changes in direction is known as:
inertia
The more mass a substance has the more force is required to move it or to change its direction. This resistance to changes in direction is known as inertia.
What is the primary difference between internal and external combustion engines?
where the power is developed
The primary difference between internal and external combustion engines lies in where the power is developed. In an internal combustion engine fuel is ignited and burned inside the same container where the power is developed while in an external combustion engine the fuel is ignited outside the engine and the resulting power sent to it.
The steering __________ transfers the motion of the steering gear output shaft to the steering arms that turn the wheels.
linkage
The steering linkage is a system of pivots and connecting parts between the steering gear and the control arms. The steering linkage transfers the motion of the steering gear output shaft to the steering arms that turn the wheels.
When a car engine is running, what provides electrical current to recharge the battery and power the electrical system?
alternator
Once the engine is running, the alternator provides electrical current to recharge the battery and power the electrical system. The alternator is driven by the engine's crankshaft and produces alternating current (AC) which is then fed through a rectifier bridge to convert it to the direct current (DC) required by the electrical system. A voltage regulator controls the output of the alternator to maintain a consistent voltage (approx. 14.5 volts) in the electrical system regardless of load.
Which of the following is a relay that connects the battery to the starter motor when the ignition key is turned?
solenoid
The cylindrical solenoid is a relay that safely connects the high amperage battery to the starter motor when the ignition key is turned. This current then allows the engine to turn at a high enough speed to start.
Which of the following is the smallest component of an element that still retains the properties of the element?
atom
An atom is the smallest component of an element that still retains the properties of the element.