Applied Mechanics (Part-2) (General Engineering) (SSC JE)

Total Questions: 13

11. If u₁ and u₂ are the velocities of two moving bodies in the same direction before impact and V₁ and V₂ are their velocities after impact, then coefficient of restitution is given by [MPSC AE PRE.- 23.06.2019 ]

Correct Answer: (b)
Solution:

According to Newton's law of restitution– Coefficient of restitution (e)

12. The damping force acts on the moving system of an indicating instrument only when it is [RRB S.S.E. (Secunderabad) 02.09.2015 (Shift-I) ]

Correct Answer: (a) Moving
Solution:

The damping force acts on the moving system of an indicating instrument only when it is moving The damping torque in indicating can be provided by– Air friction damping is use for low magnetic field.

Example–Moving iron an electrodynamometer tape instrument.
• Fluid friction damping is preferred where medium value of magnetic field is used ex-electrostatic instrument.
• Eddy current damping is preferred when high/strong magnetic field is used. Example PMMC and induction type instrument.

13. A frictionless pin joint transmits a [BPSC AE (GEN. ENGG.) 16.09.2018 ]

Correct Answer: (a) Force which passes through the pin
Solution:

A frictionless pin joint transmit a force which passes through the pin.
• Pin joints in truss can transmit forces, but not moments, so members do not bend.
Angle θ is free to change during loading
• Rigid joints in frames can transmit forces and moments.
So there is bending in members.
Angle θ remains fixed during loading.