This set of Railway Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Rail Flaw Detection”.
1. How can rail flaws be detected?
a) By visual examination
b) By rail flaw detection equipment
c) By visual examination or equipment
d) By using chemicals
Explanation: Flaws are the defects which can lead to fracture of rails. Thus their detection is important and can be done visually or with the help of equipment.
2. What is another name of Ultrasonic rail flaw detection technique?
a) Non-destructive method of testing
b) Destructive method of testing
c) Method of visual examination
d) Metallurgical flaw detection
Explanation: The rails/joints are not opened in USFD method. This method is also called Non-destructive method of testing of rails.
3. What is the minimum frequency of ultrasonic waves?
a) 20,000 cycles per second
b) 25,000 cycles per second
c) 31,400 cycles per second
d) 25,000 cycles per minute
Explanation: Ultrasonic waves are the waves having frequency more than 20,000 cycles per second. They follow principles of reflection, refraction and transmission.
4. How defects are identified using ultrasonic waves?
a) They pass through the flaw
b) They reflect back from the flaw
c) They give sound when encountered a flaw
d) They release heat at location of flaw
Explanation: When the ultrasonic waves detect a flaw they have a property of reflecting back. This is used for detection of defects in the rail.
5. Crystal transducers are used for ________
a) Production of ultrasonic frequency
b) Measuring the cracks in rails
c) Shaping the wheels
d) Production of sound
Explanation: Crystal transducers are made of Barium or Quartz and are the simplest method used for production of ultrasonic frequency. This is then used for detection of flaws.
6. Which probe is suitable for detecting horizontal and inclined flaws?
a) Normal probe
b) Angle probe
c) Semi normal probe
d) Crystal probe
Explanation: Normal probes transmit the ultrasonic waves in downward direction. They can be used to detect horizontal, inclined flaws and bolt hole cracks.
7. Which of the following techniques is used by Indian railways for ultrasonic testing?
c) Frequency modulation
d) Acoustic range
Explanation: Different techniques are adopted depending on the type of equipment involved. Indian railway uses pulse echo as well as frequency modulation methods.
8. How is the echo arising due to fault determined using pulse echo system?
a) By its relative position
b) By its amplitude
c) By its range
d) By its relative position and amplitude
Explanation: When ultrasonic waves are sent they may have more than one reflection. But the one corresponding to a fault is easily recognized by its relative position and amplitude.
9. What does IMR stand for in the classification of Rail flaws?
a) Immediate removal
b) Intentional removal
c) Intermediate repetition
d) Incremental repetition
Explanation: IMR stands for immediate removal. These flaws are serious in nature and can lead to accidents. Rails having such flaws should be replaced quickly.
10. What type of defect is OBS defect?
a) Not so serious
b) Immediate removal
c) Warning of early removal
d) Safe rail
Explanation: OBS stands for observe. These defects are not so serious and rail has to be kept under observation.
11. An OBS(E) designation represents a defect ______
a) On major bridges
b) Within the fish plate
c) Anywhere on the track
d) At joints
Explanation: A defect around 100m from approach of a bridge is designated as OBS(B). OBS(E) stands for defect within fish plate zone.
12. Which of the following can be used for testing of long railway tracks?
a) German rail testing car
b) Manual methods
c) Rail testing trolley
d) Mechanical gauges
Explanation: Rail testing trolley can test only 2-3 km of rail in a day. Thus German rail testing car can be used which tests around 200km per day efficiently.
13. What is the frequency prescribed for the need based concept of the ultrasonic testing?
a) 15 GMT
b) 8 GMT
c) 10 GMT
d) 6 GMT
Explanation: The inspection of rails can be done after the passage of every 8GMT of load. Thus, frequency for need based ultrasonic testing is 8GMT.
14. In frequency modulation technique cracks below bolt holes are not detected.
Explanation: Cracks completely below the bolt holes remain undetected by the frequency modulation technique. This is because of the interruptions caused by the hole.
15. What does SPURT stand for in SPURT car procured by the Indian railways?
a) Self-propelled Ultrasonic Rail Testing
b) Self-programmed Ultrasonic Rail Testing
c) Satellite Proposed Universal Rail Testing
d) Series Processed Unit for Rail Testing
Explanation: SPURT stands for Self-propelled Ultrasonic Rail Testing car. It is used for detecting, analysing, recording the internal defects in the rails.
Sanfoundry Global Education & Learning Series – Railway Engineering.
To practice all areas of Railway Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.