Machine Dynamics Questions and Answers for Entrance exams on “Balancing of Coupled Locomotives & Secondary Forces of Multi-cylinder Inline Engines”.
1. In a coupled locomotive, the driving wheels are connected to the leading and trailing wheels by a/an __________
a) Outside coupling rod
b) Inside coupling rod
c) Backside coupling rod
d) Frontend coupling rod
Answer: a
Clarification: In a coupled locomotive, the driving wheels are connected to the leading and trailing wheels by an outside coupling rod.
2. For a coupled locomotive, the driving wheels and the leading and trailing wheels are connected by an inside coupling rod.
a) True
b) False
Answer: b
Clarification: In a coupled locomotive, the driving wheels are connected to the leading and trailing wheels by an outside coupling rod.
3. On connecting a wheel through outside coupling rod, which utility comes of use?
a) Tractive
b) Swaying
c) Hammer
d) Piston
Answer: a
Clarification: For a coupled locomotive, the driving wheels and the leading and trailing wheels are connected by an outside coupling rod. A significantly greater portion of the engine mass is utilized by tractive purposes.
4. In coupled locomotives, the coupling rod cranks are placed diametrically opposite to the adjacent ________
a) Driving cranks
b) Driving rods
c) Driving piston
d) Driving valves
Answer: a
Clarification: In coupled locomotives, the coupling rod cranks are placed at a position which is diametrically opposite to the adjacent driving cranks which are also known as the main cranks.
5. Coupling rods with connecting rods and pins can be treated as ________
a) Rotating masses
b) Masses in linear motion
c) Reciprocating masses
d) Massless
Answer: a
Clarification: The coupling rods together along with cranks and pins can be treated as rotating masses, and completely balanced by masses in the respective wheels i.e trailing, driving and leading.
6. The variation of pressure between the wheel and the rail (i.e. hammer blow) may be reduced by _______
a) Equal distribution of balanced masses
b) More mass towards driving wheel
c) More mass towards trailing wheel
d) More mass towards leading wheel
Answer: a
Clarification: The variation of pressure between the wheel and the rail also known as hammer blow, it can be reduced by equal distribution of the balanced mass between the three wheels i.e driving, leading and trailing wheels respectively.
7. In coupled locomotives, where are the coupling rod cranks placed with respect to the main crank?
a) Diametrically opposite
b) At 90 degrees
c) At 60 degrees
d) At 120 degrees
Answer: b
Clarification: In coupled locomotives, the coupling rod cranks are placed at a position which is diametrically opposite to the adjacent main cranks (i.e. driving cranks).
8. If the connecting rod is not too long, then which of the following phenomenon occurs?
a) Secondary disturbing forces
b) Primary disturbing forces
c) Secondary stabilizing forces
d) Primary stabilizing forces
Answer: a
Clarification: When the connecting rod isn’t too long or in other words when the obliquity of the connecting rod is taken into consideration, then the secondary disturbing force due to the reciprocating mass arises.
9. When the connecting rod is too long, secondary forces arise due to reciprocating masses.
a) True
b) False