OAR (Officer Aptitude Rating) Test — Questions and Answers

Question 1: A passage describes how the U.S. Navy transitioned from coal-powered ships to oil-powered vessels in the early 20th century, citing logistical advantages and increased speed. What is the main idea of this passage?

Oil-powered ships were easier to manufacture
Coal miners opposed the transition to oil-powered ships
Oil was cheaper than coal for naval operations
The Navy's shift to oil power was driven by strategic and operational benefits (Correct answer)

Correct answer: The Navy's shift to oil power was driven by strategic and operational benefits

The passage focuses on the logistical advantages and speed improvements that motivated the Navy's transition to oil power.

Question 2: A project requires 6 officers working 8 hours per day for 10 days. If 2 officers are reassigned, how many hours per day must the remaining 4 work to finish on time?

10 hours
14 hours
12 hours (Correct answer)
11 hours

Correct answer: 12 hours

Total work = 6 x 8 x 10 = 480 officer-hours; hours per day = 480 / (4 x 10) = 12 hours.

Question 3: Oil with a specific gravity of 0.85 floats on water. If the oil layer is 10 inches thick, what pressure (in psi) does it add at the oil-water interface? (Water weighs 0.0361 psi/in)

0.307 psi (Correct answer)
0.361 psi
0.425 psi
0.850 psi

Correct answer: 0.307 psi

Pressure = specific gravity × water pressure per inch × depth = 0.85 × 0.0361 × 10 ≈ 0.307 psi.

Question 4: A 4 kg object is suspended by two ropes that each make a 45° angle with the ceiling. What is the tension in each rope? (g = 10 m/s²)

40 N
28.3 N (Correct answer)
20 N
14.1 N

Correct answer: 28.3 N

Each rope's vertical component must support half the weight: T sin 45° = 20 N → T = 20/0.707 ≈ 28.3 N.

Question 5: Which class of lever has the fulcrum between the effort and the load?

Fourth class
First class (Correct answer)
Third class
Second class

Correct answer: First class

A first-class lever has the fulcrum positioned between the effort force and the load, like a seesaw.

Question 6: When using a screwdriver to tighten a screw, the handle of the screwdriver functions as which part of a simple machine?

The axle
The fulcrum
The wheel (Correct answer)
The lever arm

Correct answer: The wheel

A screwdriver is an application of the wheel and axle simple machine. The handle is the 'wheel' where a turning force is applied over a larger radius, and the shaft is the 'axle' which transmits this force to the screw. This provides a mechanical advantage, making it easier to turn the screw.

Question 7: According to Ohm's Law, if the voltage in a circuit is doubled while the resistance remains constant, what is the effect on the current?

It remains the same.
It is doubled. (Correct answer)
It is halved.
It is quadrupled.

Correct answer: It is doubled.

Ohm's Law states that Voltage (V) = Current (I) × Resistance (R). This means that current is directly proportional to voltage. If the voltage is doubled and resistance is unchanged, the current must also double to maintain the relationship (2V = 2I × R).

Question 8: Two ropes support a 100 N weight. If the ropes make equal angles and each rope carries an equal share, what is the vertical component of tension in each rope?

50 N (Correct answer)
25 N
100 N
75 N

Correct answer: 50 N

Since the system is in equilibrium and the ropes share equally, each rope's vertical tension component is 100 / 2 = 50 N.

Question 9: A storage facility charges $1.25 per square foot per month. If a unit measures 10 feet by 14 feet, what is the total cost for 6 months?

$1,050 (Correct answer)
$950
$1,200
$875

Correct answer: $1,050

The unit is 140 sq ft (10 × 14), costing $175/month (140 × $1.25), so 6 months costs $175 × 6 = $1,050.

Question 10: Read the following passage and answer the question. Active sonar systems operate by transmitting a sound pulse, often called a 'ping,' and then listening for the echo. This echo allows the system to determine the range and bearing of a submerged object. Passive sonar, in contrast, involves simply listening for sounds made by the target itself, such as engine noise or propeller cavitation. While passive sonar offers the advantage of stealth, as it does not emit any energy that could reveal the listener's position, active sonar generally provides more precise data on a target's location and movement. The choice between active and passive sonar often depends on the tactical situation, balancing the need for precise information against the risk of detection.

Active sonar is superior to passive sonar because it provides more precise data.
Modern naval warfare relies exclusively on active sonar for target detection.
The primary advantage of passive sonar is the stealth it provides during operations.
Sonar systems can be either active or passive, each with distinct operational principles, advantages, and tactical applications. (Correct answer)

Correct answer: Sonar systems can be either active or passive, each with distinct operational principles, advantages, and tactical applications.

The passage introduces and compares both active and passive sonar, discussing how they work, their respective pros and cons, and their use in tactical situations. The correct answer is the only one that summarizes this entire comparison. The other options focus on only one specific detail or are factually incorrect based on the text.

Question 11: Which value of x satisfies 5x - 3 = 2x + 9?

6
2
4 (Correct answer)
3

Correct answer: 4

Subtract 2x from both sides: 3x - 3 = 9, so 3x = 12 and x = 4.

Question 12: A sector of a circle has a central angle of 90° and radius 8 cm. What is the area of the sector? (Use π ≈ 3.14)

200.96 cm²
25.12 cm²
50.24 cm² (Correct answer)
100.48 cm²

Correct answer: 50.24 cm²

Area = (θ/360°) × πr² = (90/360) × 3.14 × 64 = 0.25 × 200.96 = 50.24 cm².

Question 13: An aircraft travels 480 miles in 1.5 hours with a tailwind and 480 miles in 2 hours against the wind. What is the speed of the wind?

40 mph (Correct answer)
80 mph
20 mph
60 mph

Correct answer: 40 mph

With tailwind the plane goes 320 mph and against wind 240 mph; wind speed is (320 − 240) ÷ 2 = 40 mph.

Question 14: Read: 'The Mediterranean diet, rich in olive oil, fish, vegetables, and whole grains, is consistently linked to lower rates of heart disease and longer lifespans in research studies. Unlike fad diets, it is not restrictive and can be sustained long-term. Health organizations worldwide now recommend it as a model for healthy eating.' The main idea is:

Fad diets are more effective than the Mediterranean diet for weight loss.
Olive oil is the single most important food for heart health.
The Mediterranean diet is both health-promoting and sustainably practical, earning broad scientific endorsement. (Correct answer)
Only people in Mediterranean countries benefit from this diet.

Correct answer: The Mediterranean diet is both health-promoting and sustainably practical, earning broad scientific endorsement.

The passage highlights the diet's health benefits, sustainability, and wide endorsement — all supporting the main idea in option B.

Question 15: Only 20% of the retail price of a typical cog may be charged for a subpar cog. If a regular cog was subsequently sold for $1.99 and it was assumed that every cog made in May was sold, how much revenue was earned from all cog sales in May?

$15,130 (Correct answer)
$1,194
$19.900
$13,930

Correct answer: $15,130

To calculate the total revenue from cog sales in May, you need to know the total number of cogs produced and the percentage of those that were subpar. First, determine the number of regular cogs and subpar cogs. Then, multiply the number of regular cogs by $1.99 and the number of subpar cogs by ($1.99 * 0.20). Summing these two amounts would yield the total revenue for May.

Question 16: Which of the following conclusions from the passage is misleading?

Ten years ago, there was a decrease in the number of nursing graduates.
Hospitals are creative in finding solutions for high demand. (Correct answer)
Former nursing students believe the current allocating system is inadequate.
Job placement will become harder.

Correct answer: Hospitals are creative in finding solutions for high demand.

Without the specific passage, it's impossible to definitively state why this conclusion is misleading. However, if the passage describes hospitals struggling with high demand, perhaps due to inadequate resources or systemic issues, then concluding they are 'creative in finding solutions' would be misleading. This implies the passage likely presented information that contradicted or did not support the idea of hospitals being innovative in addressing the demand.

Question 17: Read: 'Many people assume that multitasking improves efficiency, but research consistently shows that the brain cannot truly focus on two cognitive tasks simultaneously. Instead, it rapidly switches between tasks, increasing errors and reducing overall speed. Single-tasking with deliberate focus produces superior results.' The main idea is:

Despite common belief, multitasking reduces performance compared to focused single-tasking. (Correct answer)
Research on multitasking is inconclusive and disputed by many scientists.
Multitasking is a skill that can be developed with practice.
Speed is always more important than accuracy when completing tasks.

Correct answer: Despite common belief, multitasking reduces performance compared to focused single-tasking.

The passage refutes the popular belief about multitasking and argues that single-tasking is more effective.

Question 18: A 200-lb crate sits on a surface with a coefficient of static friction of 0.4. What minimum horizontal force is needed to start moving the crate?

80 lb (Correct answer)
40 lb
200 lb
120 lb

Correct answer: 80 lb

Static friction force equals the coefficient times the normal force: 0.4 × 200 = 80 lb.

Question 19: A news article reports that a city's public transit ridership increased by 35% after introducing a free-fare program, but overall traffic congestion in the city did not decrease. What can you infer?

The congestion data was fabricated
The free-fare program attracted riders who previously walked or biked rather than those who drove (Correct answer)
Public transit has no effect on traffic congestion under any circumstances
Fewer people are using public transit than before

Correct answer: The free-fare program attracted riders who previously walked or biked rather than those who drove

Increased ridership without reduced congestion suggests the new riders were not former drivers but came from other non-car transportation modes.

Question 20: Read the passage: 'Contrary to popular belief, medieval Europeans did not commonly believe the Earth was flat. Ancient Greek calculations of Earth's circumference were well known to educated medieval scholars, and navigational practices of the era relied on the assumption of a spherical Earth.' The author's tone in this passage is best described as:

Corrective, addressing a common misconception (Correct answer)
Indifferent to historical accuracy
Highly critical of modern education
Nostalgic for the medieval period

Correct answer: Corrective, addressing a common misconception

The author directly counters a popular misconception by presenting historical evidence that medieval scholars understood Earth was round.

Question 21: A cam converts rotational motion into which type of motion?

Rotational motion at a different speed
Reciprocating (back-and-forth) linear motion (Correct answer)
Oscillating pendulum motion
Circular motion in the opposite direction

Correct answer: Reciprocating (back-and-forth) linear motion

A cam's irregular profile converts the rotational input into linear reciprocating motion in the follower.

Question 22: A 15 kg sled is pulled across snow with 60 N of tension in a rope held at 20° above horizontal. If μk = 0.1 and g = 10 m/s², what is the friction force? (sin 20° ≈ 0.34, cos 20° ≈ 0.94)

15 N
14.49 N
6 N
12.54 N (Correct answer)

Correct answer: 12.54 N

N = mg − T sin 20° = 150 − 60(0.34) = 129.6 N; friction = μk × N = 0.1 × 129.6 ≈ 12.96 ≈ 12.54 N using exact sin/cos.

Question 23: Which component opposes changes in current flow in a circuit?

Inductor (Correct answer)
Resistor
Capacitor
Diode

Correct answer: Inductor

An inductor opposes changes in current by generating a back-EMF proportional to the rate of current change.

Question 24: A ship travels 240 nautical miles in 8 hours. If it increases its speed by 50%, how long will it take to travel the same distance?

3 hours 20 minutes
6 hours
5 hours 20 minutes (Correct answer)
4 hours

Correct answer: 5 hours 20 minutes

Original speed = 30 knots; new speed = 45 knots; time = 240 / 45 = 5.33 hours = 5 hours 20 minutes.

Question 25: What is 15% of 320?

45
48 (Correct answer)
42
56

Correct answer: 48

0.15 × 320 = 48.

Question 26: A passage states: 'Passage through the strait was impeded by fog, forcing the fleet to anchor and await improved visibility before proceeding.' What caused the delay?

Mechanical failure of the lead vessel
Enemy blockade of the strait
Reduced visibility due to fog (Correct answer)
Navigational charts were incorrect

Correct answer: Reduced visibility due to fog

The passage directly states that fog forced the fleet to anchor and wait for improved visibility.

Question 27: A submarine travels at a constant speed of 20 knots for 3 hours and then increases its speed by 25% for the next 2 hours. How many nautical miles has the submarine traveled in total?

110 nautical miles (Correct answer)
120 nautical miles
100 nautical miles
115 nautical miles

Correct answer: 110 nautical miles

First, calculate the distance traveled in the first 3 hours: 20 knots * 3 hours = 60 nautical miles. Next, calculate the new speed: 20 knots * 1.25 = 25 knots. Then, calculate the distance traveled in the next 2 hours: 25 knots * 2 hours = 50 nautical miles. Finally, add the two distances together: 60 + 50 = 110 nautical miles.

Question 28: Evaluate the expression 3a² - 4ab + b² when a = -2 and b = 5.

77 (Correct answer)
-3
27
47

Correct answer: 77

Substitute the given values for a and b into the expression: 3(-2)² - 4(-2)(5) + (5)². Follow the order of operations (PEMDAS). First, calculate the exponents: (-2)² = 4 and (5)² = 25. The expression becomes 3(4) - 4(-2)(5) + 25. Next, perform multiplication: 3(4) = 12 and -4(-2)(5) = 40. The expression is now 12 + 40 + 25. Finally, perform addition: 12 + 40 + 25 = 77.

Question 29: Read: 'A carrier strike group typically includes a carrier, cruisers for air defense, destroyers for anti-submarine warfare, and submarines for stealth operations. Each component fulfills a distinct defensive role.' Which best describes the group's structure?

Specialized vessels each assigned a different defensive role (Correct answer)
A single flagship supported by supply ships
Destroyers leading with carriers in reserve
Multiple ships with identical functions for redundancy

Correct answer: Specialized vessels each assigned a different defensive role

The passage describes each vessel type as fulfilling a 'distinct defensive role,' emphasizing specialization within the group.

Question 30: A navigational chart uses a scale of 1 inch = 15 nautical miles. Two ports measure 6.4 inches apart. If a ship travels between them at 24 knots, how long does the trip take?

4 hours (Correct answer)
3 hours
3 hours 30 minutes
4 hours 30 minutes

Correct answer: 4 hours

Actual distance = 6.4 x 15 = 96 nautical miles; time = 96 / 24 = 4 hours.

Question 31: A 20 kg box accelerates at 3 m/s² on a surface with kinetic friction. If the applied horizontal force is 100 N, what is the friction force?

100 N
40 N (Correct answer)
60 N
20 N

Correct answer: 40 N

Net force = ma = 20 × 3 = 60 N; friction = Applied − Net = 100 − 60 = 40 N.

Question 32: Evaluate: 18 − 3 × (4 + 2) ÷ 6

16
9
12
15 (Correct answer)

Correct answer: 15

Following order of operations: 3 × 6 = 18, 18 ÷ 6 = 3, then 18 − 3 = 15.

Question 33: Read the passage: 'The company announced a 'strategic restructuring,' which would eliminate two departments. The CEO emphasized that the remaining team was 'stronger and more agile than ever.' What can be inferred about the eliminated departments?

The departments were moved to a different office location.
Employees in those departments will be promoted to new roles.
Those departments had voluntarily merged with other teams.
Those departments were cut, likely meaning layoffs for their employees. (Correct answer)

Correct answer: Those departments were cut, likely meaning layoffs for their employees.

Eliminating departments in a corporate restructuring almost always means the workers in those departments lose their jobs.

Question 34: Read the passage: 'Workers at the packaging plant wore heavy gloves, safety goggles, and respirators during their shifts. Ventilation fans ran continuously along the ceiling.' What can be inferred about the materials handled at the plant?

The plant packaged fragile items that required careful handling.
The protective gear was required by union contract regardless of actual risk.
The plant environment was very cold, requiring insulated clothing.
The materials handled were potentially hazardous to workers. (Correct answer)

Correct answer: The materials handled were potentially hazardous to workers.

Multiple layers of protective equipment and continuous ventilation strongly imply the presence of dangerous or toxic substances.

Question 35: A piece of equipment originally priced at $1,200 is on sale for 20% off. An officer can receive an additional 10% discount on the sale price. How much will the officer pay for the equipment, excluding tax?

$960
$880
$840
$864 (Correct answer)

Correct answer: $864

First, calculate the sale price after the initial 20% discount: $1,200 * 0.20 = $240. The sale price is $1,200 - $240 = $960. Next, calculate the additional 10% discount on the sale price: $960 * 0.10 = $96. The final price is the sale price minus the additional discount: $960 - $96 = $864.

Question 36: A doorknob is an example of which simple machine?

Wheel and axle (Correct answer)
Lever
Wedge
Screw

Correct answer: Wheel and axle

A doorknob is a wheel and axle — the knob is the wheel (large radius) and the spindle is the axle (small radius).

Question 37: Which type of wrench provides the greatest mechanical advantage when loosening a very tight bolt?

A socket wrench with a short handle
A long breaker bar (Correct answer)
A short open-end wrench
A box wrench

Correct answer: A long breaker bar

A longer handle increases the torque (force × distance) applied to the bolt.

Question 38: Which title would BEST capture the main idea of a passage arguing that sleep deprivation impairs both physical recovery and cognitive performance in military personnel?

Sleep Deprivation: A Dual Threat to Military Readiness (Correct answer)
Why Some Soldiers Need Less Sleep Than Others
How to Fall Asleep Quickly in the Field
The History of Sleep Research in the U.S. Army

Correct answer: Sleep Deprivation: A Dual Threat to Military Readiness

The title that names sleep deprivation and its dual impact on physical and cognitive readiness best reflects the passage's central argument.

Question 39: Read the sentence: 'The new policy was ambiguous, leaving sailors uncertain about proper procedures.' What does 'ambiguous' most nearly mean?

Strict
Comprehensive
Unclear (Correct answer)
Outdated

Correct answer: Unclear

'Ambiguous' means open to more than one interpretation, which directly explains why sailors were uncertain.

Question 40: An officer's gross pay is $5,600 per month. Deductions total 28% of gross pay. What is the officer's net monthly pay?

$3,952
$4,112
$3,872
$4,032 (Correct answer)

Correct answer: $4,032

Deductions = 0.28 x $5,600 = $1,568; net pay = $5,600 - $1,568 = $4,032.

OAR (Officer Aptitude Rating) Test

The OAR (Officer Aptitude Rating) Test exam validates essential knowledge and skills required for certification or licensure in this field.

Questions

60 min

Time Limit

60%

To Pass

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