ASVAB Mechanical Comprehension Practice Test 387467 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.54
Score	0%	71%

Review

1 If input effort is 200 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 3?

79% Answer Correctly

	66ft⋅lb
	1200ft⋅lb
	300ft⋅lb
	600 ft⋅lb

Solution

Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 3 will multiply an input effort of 200 ft⋅lb by 3 to produce an output effort of 600 ft⋅lb.

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

61% Answer Correctly

	increase, increase
	decrease, decrease
	decrease, increase
	increase, decrease

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.

What type of load acts on a relatively small area of a structure?

74% Answer Correctly

	dynamic load
	impact load
	concentrated load
	non-uniformly distributed 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.

What type of load varies with time or affects a structure that experiences a high degree of movement?

65% Answer Correctly

	static load
	impact load
	dynamic load
	concentrated load

Solution

5 If you have a gear train with two gears, the first with 32 teeth and the second with 16 teeth, how many revolutions does the second gear make for each revolution of the first gear?

77% Answer Correctly

	-3
	6
	2
	1

Solution

The gear ratio (V_r) of a gear train is the product of the gear ratios between the pairs of meshed gears. Let N represent the number of teeth for each gear:

V_r = \( \frac{N_1}{N_2} \) \( \frac{N_2}{N_3} \) \( \frac{N_3}{N_4} \) ... \( \frac{N_n}{N_{n+1}} \)

In this problem, we have only two gears so the equation becomes:

V_r = \( \frac{N_1}{N_2} \) = \( \frac{32}{16} \) = 2