A. Varies in magnitude but constant in direction
B. Varies in direction but constant in magnitude
C. Varies in magnitude and direction both
D. Constant in magnitude and direction both
Answer: Option A
This Question Belongs to Mechanical Engineering >> Theory Of Machine
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
The unbalance force due to reciprocating masses is given by m w^2 r ( cos theta + (cos 2 theta )/n), Which depends on value of theta so unbalance force is positive for Half crank rotation and positive for other Half. So force chqnges magnitude and direction both.