This set of Railway Engineering Interview Questions and Answers for Experienced people focuses on “Forces Acting on the Track”.
1. Which of the following is not a type of force acting on the track?
a) Vertical load
b) Lateral force
c) Magnetic force
d) Contact stresses
Explanation: The movement of locomotive on the track introduces various types of forces in it. These forces include Vertical loads, Lateral and longitudinal forces, Contact stresses, etc. There is absence of Magnetic field and thus no magnetic force.
2. Why is the value of dynamic load much more than that of static load?
a) Due to impact of speed and rail vibrations
b) Additional live load during motion
c) More traffic
d) Both loads are same
Explanation: When the train is in motion additional load due to speed and vibrations in rail are experienced. Due to these factors accompanying the motion of the train, the dynamic load is more than the static load.
3. What is the German formula for the speed factor of the train?
Explanation: The dynamic load is more than the static load of the train. To find the dynamic load the static load is increased by a factor called the speed factor. The German formula for the speed factor of the train is V2/30,000.
4. Which is the major force developed due to revolving masses like pins and coupling rods in the wheel?
a) Centrifugal force
b) Vertical force
c) Lateral force
d) Centripetal force
Explanation: The crank pins and coupling rods make the centre of mass of the wheel to shift from its position. This creates an unbalanced force in the system which acts away from the centre of the wheel.
5. How is the lateral displacement of rail balanced?
a) By coning of wheels
b) By friction between rail and sleeper
c) By manual means
d) By electrical equipment
Explanation: The lateral deflection of the train causes huge development of bending moment in the wheels. This is balanced by the friction between rail and sleeper, ballast and rail and opposition presented by the fastenings.
6. Hammer blow effect is because of the _____
a) revolving masses like crank pins, coupling rods
b) weight added to balance the reciprocating masses
c) difference in elevation of inner and outer rail
d) cant deficiency
Explanation: The weight added to compensate the reciprocating masses tries to throw the wheel outwards. This causes pressure variation in the wheel and is known as Hammer blow effect.
7. In the Hammer blow effect formula H = Mr(2πn)2 sinꬾ/g, what does n stand for?
a) Crank pin diameter
b) Number of revolutions
c) Number of revolutions per second
d) Number of wheels in locomotive
Explanation: In the above equation, n stands for number of revolutions of the wheel per second. The diameter of the crank pin is ‘r’ and ‘ꬾ’ is the crank angle.
8. The maximum combined force of the Hammer blow, inertia of driving wheel, steam effect do not act simultaneously due to phase difference in position of counterweights.
Explanation: All these forces have different positions in wheel and thus have difference in phases. Thus they cannot obtain maximum value at the same time.
9. As per the theory of Hertz the rail and wheel contact is similar to the contact between _____
a) two cylinders
b) a cylinder and a sphere
c) a sphere and a cube
d) two spheres
Explanation: The circular wheel is in contact with the curved surface of the wheel and their axes are at right angles to each other. According to the theory proposed by Hertz it depicts similar contact like two cylinders.
10. The pattern of distribution of load under the sleepers does not depend on which of the following factors?
a) Firmness of packing
b) Cost of construction
d) Standard of maintenance
Explanation: The load pattern depends on the nature of load, the firmness of the packing under the sleeper and their maintenance. Distribution of load does not depend on the cost of construction.
11. What is Photo-elastic method used for?
a) For measuring stresses on the rail
b) For measuring strain of the rail
c) For calculating depth of ballast
d) For Reconnaissance survey
Explanation: Photo-elastic method is used for measuring stresses on the rail. Indian railway mostly uses Electric resistance strain gauge method for the measurement of stresses.
Sanfoundry Global Education & Learning Series – Railway Engineering.
To practice all areas of Railway Engineering for Interviews , here is complete set of 1000+ Multiple Choice Questions and Answers.