ASVAB Mechanical Comprehension Practice Test 949038 Results

Your Results Global Average
Questions 5 5
Correct 0 3.00
Score 0% 60%

Review

1

Which class of lever is used to increase force on an object in the same direction as the force is applied?

53% Answer Correctly

third

second

all of these

first


Solution

A second-class lever is used to increase force on an object in the same direction as the force is applied. This lever requires a smaller force to lift a larger load but the force must be applied over a greater distance. The fulcrum is placed at one end of the lever and mechanical advantage increases as the object being lifted is moved closer to the fulcrum or the length of the lever is increased. An example of a second-class lever is a wheelbarrow.


2

What type of load is sudden and for a relatively short duration?

69% Answer Correctly

impact load

non-uniformly distributed load

concentrated load

dynamic load


Solution

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.


3

What's the first gear in a gear train called?

57% Answer Correctly

idler gear

driver gear

input gear

driven gear


Solution

A gear train is two or more gears linked together. Gear trains are designed to increase or reduce the speed or torque outpout of a rotating system or change the direction of its output. The first gear in the chain is called the driver and the last gear in the chain the driven gear with the gears between them called idler gears.


4

Which of the following is not a characteristic of a ceramic?

61% Answer Correctly

low density

chemically stable

low corrosive action

high melting point


Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.


5

Two gears are connected and the smaller gear drives the larger gear. The speed of rotation will __________ and the torque will __________.

61% Answer Correctly

decrease, decrease

increase, decrease

increase, increase

decrease, increase


Solution

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.