RRaahUPSC
2013 · Science & TechnologyPrevious Year Question
Q38.
Ball bearings are used in bicycles, cars, etc., because
A. the actual area of contact between the wheel and axle is increased
B. the effective area of contact between the wheel and axle is increased
C. the effective area of contact between the wheel and axle is reduced
D. None of the above statements is correct
Answer

C

Explanation

The roundness of the bearings creates less contact between the bearing and the object being moved. A reduction in contact area means less friction.
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