1. 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.
2. Which of the following techniques is used by Indian railways for ultrasonic testing?
a) Transmission
b) Resonance
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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. In frequency modulation technique cracks below bolt holes are not detected.
a) true
b) false
Explanation: Cracks completely below the bolt holes remain undetected by the frequency modulation technique. This is because of the interruptions caused by the hole.
10. 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.