The static balancing is satisfactory for low speed rotors but with increasing speeds, dynamic balancing becomes necessary. This is because, the
A. Unbalanced couples are caused only at higher speeds
B. Unbalanced forces are not dangerous at higher speeds
C. Effects of unbalances are proportional to the square of the speed
D. Effects of unbalances are directly proportional to the speed
Answer: Option C
In considering friction of a V-thread, the virtual coefficient of friction (μ1) is given by
A. μ1 = μsinβ
B. μ1 = μcosβ
C. $${\mu _1} = \frac{\mu }{{\sin \beta }}$$
D. $${\mu _1} = \frac{\mu }{{\cos \beta }}$$
The lower pairs are _________ pairs.
A. Self-closed
B. Force-closed
C. Friction closed
D. None of these
In a coupling rod of a locomotive, each of the four pairs is a ________ pair.
A. Sliding
B. Turning
C. Rolling
D. Screw
A kinematic chain is known as a mechanism when
A. None of the links is fixed
B. One of the links is fixed
C. Two of the links are fixed
D. None of these

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