Plus printable tests, Q&A, and an ad-free upgrade. Have a suggestion? Please let us know what you want!
Take an ASVAB Practice Test
Sample Practice Test Questions
Which of the following can conduct electricity under some conditions but not others?
semiconductor
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.
The advantage of using a third-class lever is that it increases:
the speed of the load
A third-class lever is used to increase distance traveled by an object in the same direction as the force applied. The fulcrum is at one end of the lever, the object at the other, and the force is applied between them. This lever does not impart a mechanical advantage as the effort force must be greater than the load but does impart extra speed to the load. Examples of third-class levers are shovels and tweezers.
Which of the following regulates the opening and closing of the intake and exhaust valves in each cylinder in time with the motion of the piston?
camshaft
The camshaft is linked to the crankshaft through a timing belt and regulates the opening and closing of the intake and exhaust valves in each cylinder in time with the motion of the piston. An engine designated OverHead Camshaft (OHC) locates the camshaft in the cylinder head. An engine with Double OverHead Camshaft (DOHC) has two camshafts, one to regulate the intake valves and one to regulate the exhaust valves.
A a seesaw / teeter-totter is an example of which of the following?
first-class lever
A first-class lever is used to increase force or distance while changing the direction of the force. The lever pivots on a fulcrum and, when a force is applied to the lever at one side of the fulcrum, the other end moves in the opposite direction. The position of the fulcrum also defines the mechanical advantage of the lever. If the fulcrum is closer to the force being applied, the load can be moved a greater distance at the expense of requiring a greater input force. If the fulcrum is closer to the load, less force is required but the force must be applied over a longer distance. An example of a first-class lever is a seesaw / teeter-totter.
Which of the following statements about solding is not true?
soldering can only join metals
Soldering is a process by which two or more items (typically metal) are joined together by melting a filler metal (solder) into the joint. An electrically powered soldering iron or soldering gun is used to melt the solder which is an alloy of lead and tin that has a melting point below the melting point of the items being joined. A chemical cleaning agent called flux is also used to clean the surfaces before soldering.
Two gears are connected and the smaller gear drives the larger gear. The speed of rotation will __________ and the torque will __________.
decrease, increase
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.
__________ results from oil buildup in the combustion chamber.
preignition
Preignition results from the buildup of fuel deposits and/or oil in the combustion chamber. These deposits increase chamber pressure and reduce heat tranfer to the coolant. The trapped heat then raises the temperature of the air-fuel mix to the point that it combusts before ignition.
Both intake and exhaust valves are closed as the piston begins moving back up from the bottom of the cylinder, compressing the air-fuel mixture in the combustion chamber which also makes it hotter. This describes which engine stroke?
compression
During the compression stroke, both intake and exhaust valves are closed as the piston begins moving back up from the bottom of the cylinder (bottom dead center or BDC). This compresses the air-fuel mixture in the combustion chamber which also makes it hotter.
Which of these is not a phase in cell division?
megaphase
Cell division is the process by which cells replicate genetic material in the nucleus and consists of several phases, beginning with interphase and ending with cytokinesis.