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Sample Practice Test Questions
Ignition timing defines the point in time at the end of the compression stroke that which of the following happens?
spark plugs fire
Ignition timing defines the point in time at the end of the compression stroke that the spark plug fires. Measured in number of degrees before top dead center (BTDC), the exact point that the spark plugs initiate combustion varies depending on the speed of the engine. The timing is advanced (the spark plugs fire a few more degrees BTDC) when the engine is running faster and retarded when it's running slower.
The formula \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) applies to which of Newton's laws?
universal gravitation
Newton's law of universal gravitation defines gravity: All objects in the universe attract each other with an equal force that varies directly as a product of their masses, and inversely as a square of their distance from each other. Expressed as a formula: \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) where r is the distance between the two objects and G is the gravitational constant with a value of 6.67 x 10-11.
A fixed pulley has a mechanical advantage of:
1
A fixed pulley is used to change the direction of a force and does not multiply the force applied. As such, it has a mechanical advantage of one. The benefit of a fixed pulley is that it can allow the force to be applied at a more convenient angle, for example, pulling downward or horizontally to lift an object instead of upward.
Too much fuel results in a __________ air-fuel mixture that burns quicker and cooler.
rich
The stoichiometric ratio defines the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air. For gasoline fuel, the stoichiometric ratio is about 14.7:1 or for every one gram of fuel, 14.7 grams of air are required. Too much air results in a lean air-fuel mixture that burns more slowly and hotter while too much fuel results in a rich mixture that burns quicker and cooler.
Which of these is not necessary for combustion?
accelerant
Combustion is the burning of an air-fuel mixture to provide energy. It requires the presence of air, fuel, and a heat source to ignite the air-fuel mixture. In the internal combustion engine that powers automobiles and trucks the combustion happens inside the engine utilzing a fuel like gasoline, diesel fuel, or natural gas.
What is the function of the alternator?
replaces the electrical energy that the car draws from the battery
An automobile's electrical system runs on DC power and the bulk of that power is supplied by the battery. The alternator converts the motion of the rotor into AC power which is then fed through the rectifier to convert it to DC power that both the car and the battery can use.
Blood is created in:
bone marrow
Blood is created in bone marrow and is made up of cells suspended in liquid plasma. Red blood cells carry oxygen, white blood cells fight infection, and platelets are cell fragments that allow blood to clot.
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.
The energy posessed by a thrown baseball is an example of what kind of energy?
kinetic
Kinetic energy is the energy posessed by a moving object. Potential energy is stored energy in a stationary object based on its location, position, shape, or state.