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Sample Practice Test Questions
The combustion chamber is enclosed by the:
cylinder head
Cylinders act as a guide for the pistons that translate the heat energy of combustion into the mechanical energy necessary to move a vehicle. Piston rings seal the piston to the cylinder to contain combustion gases and also regulate the oil distribution between the piston and cylinder wall. A cylinder head closes in the top of the cylinder forming the combustion chamber which is sealed by a head gasket (head). The head provides space for air and fuel intake valves, exhaust valves, and mounts for spark plugs and fuel injectors.
Two gears are connected and the larger gear drives the smaller gear. The speed of rotation will __________ and the torque will __________.
increase, decrease
Connected gears of different numbers of teeth are used together to change the rotational speed and torque of the input force. If the smaller gear drives the larger gear, the speed of rotation will be reduced and the torque will increase. If the larger gear drives the smaller gear, the speed of rotation will increase and the torque will be reduced.
The firing order of the cylinders in an engine can be found by:
observing the order in which the intake valves open
The firing order of the cylinders in an engine is different than the cynlinder numbers and can be found by observing the order in which the intake valves open.
The mechanical advantage of a block and tackle is equal to which of the following?
the number of pulleys
Two or more pulleys used together constitute a block and tackle which, unlike a fixed pulley, does impart mechanical advantage as a function of the number of pulleys that make up the arrangement. So, for example, a block and tackle with three pulleys would have a mechanical advantage of three.
When using a hacksaw, blades with __________ teeth are more appropriate for cutting thinner materials.
more
A hacksaw has replaceable blades and is used to cut metal. The blade type is chosen based on the material that is to be cut. Blades with larger numbers of teeth per inch are more appropriate for cutting thinner materials.
A subatomic particle found in the nucleus of an atom. It carries a positive electric charge. This desribes which of the following?
proton
A proton is a subatomic particle found in the nucleus of an atom. It carries a positive electric charge.
Which of the following is not a type of bridge?
block
The six basic bridge forms are beam, truss, arch, cantilever, cable, and suspension.
Too much air results in a __________ air-fuel mixture that burns more slowly and hotter.
lean
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.