246. The principle of direct and reverse cranks is readily applicable to
A.Primary balance
B.Partial primary balance.
C.Balancing of in-line engines
D.Balancing of radial engines

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247. The effect of hammer blow can be reduced by
A.Fully balancing the reciprocating masses
B.(b) and (c) above.
C.Using two or three pairs of wheels coupled together
D.All of the above

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248. The value of swaying couple is maximum or minimum when the crank is inclined at following angle with the line of stroke
A.135? and 45?
B.225? ar 15?.
C.225? and 1350
D.225? and 90?

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249. In balancing of coupled locomotive one has to consider following planes
A.Two planes of cylinders
B.Two planes of coupling rods
C.Two planes of driving wheels containing balance weights
D.All of the above

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250. The secondary critical speed of a shaft occurs at
A.Twice the speed of primary critical speed
B.Half the speed of primary critical speed
C.Tour times the speed of primary critical speed
D.One-fourth the speed of primary critical speed

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251. The shaft of a steam turbine is usually rotated at
A.Natural frequency of vibration
B.Much blow the natural frequency of vibration
C.Much above the natural frequency of vibration
D.There is no such criterion

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252. For 20? pressure angle, minimum number of teeth on gear will be
A.6
B.12
C.17
D.20

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