Project ForgeMachine Design
Design Against Static Load
GATE 2007
Medium
A ball bearing operating at a load F has 8000 hours of life. The life of the bearing, in hours, when the load is doubled to 2F is
- A8000
- B6000
- C4000
- 1000
Explanation
Ball bearing life varies as L∝1/F³ (cubic exponent for ball bearings). L2=L1×(F1/F2)³=8000×(1/2)³=1000 hours.
Source: GATE ME 2007 (2007)
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