ASVAB Mechanical Comprehension Practice Test 19112 Results

Your Results Global Average
Questions 5 5
Correct 0 3.36
Score 0% 67%

Review

1

Gear ratio indicates which of the following about two connected gears?

59% Answer Correctly

mechanical advantage

power conversion

work done

efficiency
Solution

The mechanical advantage (amount of change in speed or torque) of connected gears is proportional to the number of teeth each gear has. Called gear ratio, it's the ratio of the number of teeth on the larger gear to the number of teeth on the smaller gear.  For example, a gear with 12 teeth connected to a gear with 9 teeth would have a gear ratio of 4:3.

2 20 lbs. of effort is used by a machine to lift a 80 lbs. box. What is the mechanical advantage of the machine?
84% Answer Correctly
5.5
10
1
4
Solution

Mechanical advantage is resistance force divided by effort force:

MA = \( \frac{F_r}{F_e} \) = \( \frac{80 lbs.}{20 lbs.} \) = 4

3

Collinear forces:

72% Answer Correctly

act along the same line of action

act in a common plane

are unrelated to each other

pass through a common point
Solution

Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.

4

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

61% Answer Correctly

increase, decrease

decrease, decrease

decrease, increase

increase, 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.

5

Connected gears of different numbers of teeth are used together to change which of the following charasteristics of the input force?

65% Answer Correctly

rotational direction

energy

force

torque
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.