Which of the following statement is correct regarding power screws?

1.	Which of the following statement is correct regarding power screws?
A.	The efficiency of a self locking screw can not be more than 50%
B.	The efficiency of Acme (trapezoidal) thread is less than that of a square thread
C.	If the friction angle is less than the helix angle of the screw, then the efficiency will be more than 50%
D.	Both (A) and (B)
Answer» E.

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Which of the following statement is correct regarding power screws?

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