Officer Aptitude Rating (OAR) PracticeTest

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Prepare for the Officer Aptitude Rating (OAR) Test with interactive quizzes featuring multiple choice questions and detailed explanations. Enhance your skills and boost your confidence for success!

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The equation for gear revolutions is structured as r=D*R/d. What does 'D' represent?

Number of teeth on gear B
Revolutions of gear B
Number of teeth on gear A
Revolutions of gear A

The correct answer is: Number of teeth on gear A

In the equation for gear revolutions, $ r = \frac{D \cdot R}{d} $, 'D' refers to the number of teeth on gear A. This is because the formula is used to relate the revolutions of two gears in terms of their number of teeth. The relationship between the gears is driven by the fact that the gear with more teeth will experience fewer revolutions to engage the same distance as a gear with fewer teeth. Understanding that 'D' is the number of teeth on gear A allows for the calculation of how many revolutions gear A makes in relation to the revolutions of gear B, which is influenced by both the number of teeth and the diameter of each gear. This contextualizes how the physical characteristics of each gear influence their rotational movements and interactions within a mechanical system. Other choices focus on gear B and revolutions, which do play a role in gear mechanics but do not define 'D' in this specific equation. Recognizing that 'D' stands specifically for the number of teeth on gear A clarifies its role in determining the outcome of the gear revolution calculations.