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151.

In case of reciprocating engines the primary forces

152.

Hammer blow in locomotives results in

A.	Pulsating torque	B.	Uniform torque
C.	Tendency to lift wheel from rails	D.	Uneven speed
E.	Variable horizontal force

153.

In order to balance the reciprocating masses, the conditions to be satisfied are

A.	Primary forces must balance	B.	Primary couples must balance
C.	Secondary forces must balance	D.	Secondary couples must balance
E.	All above conditions must be satisfied

154.

In case of balancing problems pertaining to locomotives, the resultant unbalanced force is minimum when

A.	Half of the reciprocating masses are balanced by rotating masses	B.	1/2 of the reciprocating mass are balanced by equivalent rotating mass
C.	More than half of the reciprocating masses are balanced by rotating masses	D.	Reciprocating masses are balanced half by equivalent opposite reciprocating masses and the balance by rotating masses
E.	None of the above

155.

In case of meter gauge locomotives the distance between wheel centres is

156.

Forced vibrations

A.	Are followed by free vibrations	B.	Are preceded by free vibrations
C.	Take place at a frequency more than natural frequency	D.	Are independent of natural frequency
E.	None of the above

157.

Identify the incorrect statement if any

A.	In case of free vibrations the external force is applied at the ends only	B.	Damping is resistance to the oscillartion
C.	When the frequency of the external exciting force coincides with the natural frequency of the system, state of resonance is reached	D.	Forced vibrations are independent of natural frequency of vibration
E.	None of the above

158.

In case of reciprocating engine mechanism

A.	The primary and secondary forces have same direction	B.	The primary and secondary forces have same amplitude
C.	The ratio of magnitude of primary forces of secondary forces is 2	D.	The primary force has twoce the frequency of secondary force

159.

In case of locomotives the percentage of primary forces balanced is generally

160.

The critical speed of a shaft is affected by