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371.

Which of the following operation causes residual compressive stress on the surface of the material?

A.	Surface rolling	B.	Shot peening
C.	Induction hardening	D.	All of the above

372.

Laser treatment of components increases fatigue resistance of metals by

A.	compressing holes	B.	filling vacancies
C.	freezing discontinuities	D.	none of the above

373.

Hot isostatic pressing of metals reduces

A.	fatigue strength	B.	porosity
C.	ductility	D.	endurance limit

374.

Which of the following treatment is often recommended for parts operating under corrosive conditions?

A.	strain-aging	B.	tempering
C.	normalising	D.	all of the above

375.

Fatigue is mostly initiated at

A.	core	B.	core
C.	surface	D.	centre

376.

Which threads have better fatigue characteristics?

A.	Threads cut on lathe	B.	Threads cut by taps
C.	Threads cut by rolling

377.

Full stress reversal normally does not occur in bolted connections due to

A.	varying cross-section	B.	ridges and valleys in the form of threads
C.	pre-loading during tightening	D.	surface hardness

378.

Bolts in structures are often tightened

A.	below yield point	B.	upto 90% of yield point
C.	upto or beyond yield point	D.	upto breaking point

379.

In bolts the stress in the unthreaded area (the shank) is

A.	higher	B.	lower
C.	lower higher	D.	higher or lower

380.

For the same torque greater force is experienced in case of

fine threads

coarse threads