# Metrology of screw threads - Mechanical Engineering (MCQ) questions and answers

1)   Why are pitch errors observed in threads?

a. Lack of inspection
b. Incorrect ratio of tool work velocity
c. Interference between mating parts
d. All of the above
 Answer  Explanation ANSWER: Incorrect ratio of tool work velocity Explanation: No explanation is available for this question!

2)   Calculate diameter of best wire for a Withworth thread of M 24 x 7 mm size.

a. 4.04 mm
b. 7.8 mm
c. 3.94 mm
d. 8.08 mm
 Answer  Explanation ANSWER: 3.94 mm Explanation: No explanation is available for this question!

3)   According to Taylor's principle which type of gauge checks both size and geometric features?

a. Go gauge
b. No go gauge
c. Both a. and b.
d. None of the above
 Answer  Explanation ANSWER: Go gauge Explanation: No explanation is available for this question!

5)   Which type of errors show linear relation between cumulative pitch error and length of thread?

a. Periodic errors
b. Progressive errors
c. Both a. and b.
d. None of the above
 Answer  Explanation ANSWER: Progressive errors Explanation: No explanation is available for this question!

6)   What is used to measure the major diameter of an external thread?

a. Bench micrometer
c. One wire method
d. All of the above
 Answer  Explanation ANSWER: Bench micrometer Explanation: No explanation is available for this question!

7)   Which of the following statements is true?

a. In three wire method, each flank of a thread is touched by a wire in axial plane section and this is valid only for a thread having rank angle
b. Compression error is always subtracted from effective diameter value obtained
c. Floating carriage type of micrometer is used for two wire method ----
d. The value of θ is assumed 30o while calculating best wire diameter for Withworth thread
 Answer  Explanation ANSWER: Floating carriage type of micrometer is used for two wire method ---- Explanation: No explanation is available for this question!

8)   What effect does pitch error have on nut and bolt?

a. Major diameter of nut decreases and effective diameter of bolt increases
b. Effective diameter of nut decreases and effective diameter of bolt increases
c. Effective diameter of nut increases and effective diameter of bolt decreases
d. None of the above
 Answer  Explanation ANSWER: Effective diameter of nut decreases and effective diameter of bolt increases Explanation: No explanation is available for this question!

9)   Which type of threads are used to transmit power in one direction?