ISRO Scientist or Engineer Mechanical Dec 2017

$$\frac{a}{s^2} + (s - a)$$

$$\frac{\sqrt{\pi}}{2(s - a)}$$

$$\frac{1}{(s - a)}$$

Does not exist

1.001 mm

0.01 mm

0.001 mm

none of these

Principle of conservation of strain energy

Castigliano’s theorem

Conservation of momentum

Saint-Venant's Principle

f = 0:3 r

f = 0.5 r

f = 0.7 r

f = 0.9 r

A reverted gear train is one in which the first and last gears are on the same axis.

Train value for a gear is the ratio of productof driven tooth numbers to product of driving tooth numbers.

A planetary gear train is one in which the axes of some of the gears may have a motion.

A compound geartrain is one which has two or more gears on each axis.

Engineering stress - strain curve cannot have negative slope

Most applicable failure theory is maximum principal stress theory

Ultimate strain is the strain at ultimate stress

Strain hardening is represented by a negative slope in engineering stress strain curve

$$\frac{\tau \cos(\beta - \alpha)}{\sin \phi \cos (\phi + \beta - \alpha)}$$

$$\frac{\tau \sin(\beta - \alpha)}{\sin \phi \cos (\phi - \beta + \alpha)}$$

$$\frac{\tau \cos(\alpha - \beta)}{\sin \phi \cos (\phi - \beta + \alpha)}$$

$$\frac{\tau \sin(\alpha - \beta)}{\sin \phi \cos (\phi + \beta - \alpha)}$$

$$E = \frac{G}{2(1 + v)}$$

$$G = \frac{E}{2(1 + v)}$$

$$G = \frac{E}{2(1 - v)}$$

$$E = \frac{G}{2(1 - v)}$$

For direct impact of two bodies, coefficient of restitution is the ratio of relative velocity of approachof the two bodies to their relative velocity of separation

Conservation of angular momentum implies that total angular momentum of a system remains constant unless acted on by an external torque

Conservation of linear momentum in a given direction implies that the sum of external forces in that direction is zero

The coefficient of friction is independent of area of contact

20 kgf

10 kgf

5 kgf

8.7 kgf