Question:-
In rolling operation the maximum draft is given by (R = Radius of roll, m = coefficient of friction :
Option (A)
mR
Option (B)
mÖR
Option(C)
m2R2
Option(D)
m2R
Correct Option:
(D)
Question Solution:
In rolling operation, projected length of arc of contact
1 = Ö(R. Dh)
And a angle of contact.
\ tan a = (1/R-(Dh/2)) = {Ö(RDh) / (R-0.5Dh)}
\ R >> 0.5Dh, it can be written.
tan a » Ö(Dh/R)
since m ³ tan a
tan maximum draft is given by:
m ³ Ö(Dh/R) [\ m > tan a]
\ Dhmax = m2R
question-answer-faq-8974