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391.

Lubricant is not required in

A.	Gas bearings	B.	Hydrostatic bearings
C.	Electromagnetic bearing	D.	Foil bearing

392.

In rolling bearings lubricant viscosity

A.	is decided on the basis of load	B.	is determined by operating speed
C.	is not determined by load	D.	decides the life of bearing

393.

Failure of rolling bearings occurs mainly due to

A.	lubrication failure	B.	plastic deformation
C.	load and deformation	D.	fatigue

394.

Hysteresis and eddy current losses in bearings are typical to

A.	bearings for induction motors	B.	foil bearings
C.	high speed bearings	D.	electromagnetic bearings

395.

Life of a rolling bearing as listed in a catalogue is usually

A.	minimum expected life	B.	maximum expected life
C.	mean life	D.	none of the above

396.

The life of a ball bearing is usually given in

A.	hours of service	B.	total rpm
C.	either of (A) or (B) above	D.	none of the above

397.

The life of ball bearings as listed in catalogue represents

A.	90% survival rate	B.	75% survival rate
C.	50% survival rate	D.	25% survival rate

398.

For a bearing which of the following is maximum?

A.	Minimum life	B.	Average life
C.	Median life	D.	(A), (B) and (C) above are identical

399.

Which of the following is not the advantage of V-belts over flat belts?

A.	Less noisy	B.	Less axial space requirement
C.	Less slippage	D.	Less shock load absorption

400.

For the same power transmission, V-belts are

A.	thicker, narrow	B.	narrow, thicker
C.	thinner, wider	D.	wider, thinner