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

A natural feed journal bearing of diameter $$50mm$$ and length $$50mm$$ operating at $$20$$ revolutions/sec carries a load of $$2kN$$. The lubricant used has a viscosity of $$20mPa$$-$$s$$. The radial clearance is $$50\mu m.$$ The Sommerfeld number for the bearings is

The life of a ball bearing at a load of $$10$$ $$kN$$ is $$8000$$ hours. Its life in hours, if the load is increased to $$20$$ $$kN,$$ keeping all other conditions same, is

Match the following
List - $${\rm I}$$
(a)$$\,\,\,\,\,$$ Automobile wheel mounting on axle
(b)$$\,\,\,\,\,$$ High speed grinding spindle
(c)$$\,\,\,\,\,$$ $${\rm IC}$$ - Engine connecting rod
(d)$$\,\,\,\,\,$$ Leaf spring eye mounting

List - $${\rm II}$$
1.$$\,\,\,\,\,$$ Magneto bearing
2.$$\,\,\,\,\,$$ Angular contact bearing
3.$$\,\,\,\,\,$$ Taper roller bearing
4.$$\,\,\,\,\,$$ Hydrodynamic journal bearing
5.$$\,\,\,\,\,$$ Sintered metal bearing
6.$$\,\,\,\,\,$$ Teflon/Nylon bush