220/23

9. Which head is used to set at any required angle in the combination set ?
A) Square head B) Protractor head
C) Centre head D) Rule

10. What is the accuracy of the surface of lapped and machined surface plate ?
A) 0.001 mm B) 0.015 mm C) 0.025 mm D) 0.0025 mm

11. Which of the following statement is/are correct about BSW thread ?
i. BSW thread has an included angle of 55°.
ர்‌. Depth of the thread is 0.6134 x Pitch.
A) Onlyi B) Only ii
C) All of the above (i and ii) D) Both i and ii are not correct

12. Which of the following statement is/are correct about BA thread ?
i. BA thread has an included angle of 47.5°.
ii. BA threads are used in small screws of electrical appliances, watch screws,
screws of scientific apparatus.
A) Only B) Only ii
C) All of the above (i and ii) D) Both i and ii are not correct

13. What is the included angle of metric acme thread ?
A) 29° B) 30° C) 60° D) 45°

14. Which of the following thread, one flank is perpendicular to the axis of the thread and
the other flank is at 45° ?
A) BA thread B) Trapezoidal threads
C) Worm thread D) Buttress thread

15. Which of the following statement is/are correct about pitch diameter of a thread ?

i. It is the smallest diameter formed after an external thread is cut.

ii. It is the largest diameter over which a thread is cut in the case of an external
thread.

iii. It is the diameter of an imaginary cylinder which passes through the thread
such that the width of the space is equal to the width of the thread.

A) Onlyi B) Only ii

C) Only iii D) All of the above (i, ii and iii)