Consider the two states of stress as shown in configurations $${\rm I}$$ and $${\rm II}$$ in the figure below. From the standpoint of distortion energy (Von - Mises) criterion, which one of the following statements is true?

In a structure subjected to fatigue loading, the minimum and maximum stresses developed in a cycle are $$200$$$$MPa$$ and $$400MPa$$ respectively. The value of stress amplitude (in $$MPa$$) is ____________.

For the three bolt system shown in the figure, the bolt material has shear yield strength of $$200$$ $$MPa.$$ For a factor of safety of $$2,$$ the minimum metric specification required for the bolt is

A spur pinion of pitch diameter $$50$$ $$mm$$ rotates at $$200$$ $$rad/s$$ and transmits $$3$$ $$kW$$ power. The pressure angle of the tooth of the pinion is $${20^ \circ }$$. Assuming that only one pair of the teeth is in contact , the total force (in Newton ) exerted by a tooth of the pinion on the tooth on a mating gear is _________