Theory of Machine
The factor which affects the critical speed of a shaft is

Diameter of disc
All of the listed here
Span of shaft
Eccentricity

ANSWER DOWNLOAD EXAMIANS APP

Theory of Machine
Higher pairs are those which have

Point or line contact between the two elements when in motion
Surface contact between the two elements when in motion
Elements of pairs not held together mechanically
Two elements that permit relative motion

ANSWER DOWNLOAD EXAMIANS APP