1
GATE ME 2015 Set 3
+1
-0.3
Which of the following statements are TRUE for damped vibrations?

$$P.$$ For a system having critical damping, the value of damping ratio is unity and system does not undergo a vibratory motion.
$$Q.$$ Logarithmic decrement method is used to determine the amount of damping in a physical system.
$$R.$$ In case of damping due to dry friction between moving surfaces resisting force of constant magnitude acts opposite to the relative motion.
$$S.$$ For the case of viscous damping, drag force is directly proportional to the square of relative velocity.

A
$$P$$ and $$Q$$ only
B
$$P$$ and $$S$$ only
C
$$P,Q$$ and $$R$$ only
D
$$Q$$ and $$S$$ only
2
GATE ME 2015 Set 2
Numerical
+1
-0
In a spring-mass system the mass is m and the spring constant is $$k$$. The critical damping coefficient of the system is $$0.1$$ kg/s. In another spring mass system, the mass is $$2m$$ and the spring constant is $$8k$$. The critical damping coefficient (in kg/s) of this system is __________
3
GATE ME 2014
+1
-0.3
Critical damping is the
A
largest amount of damping for which no oscillation occurs in free vibration
B
smallest amount of damping for which no oscillation occurs in free vibration
C
largest amount of damping for which the motion is simple harmonic in free vibration
D
smallest amount of damping for which the motion is simple harmonic in free vibration
4
GATE ME 2014
+1
-0.3
In vibration isolation, which one of the following statements is NOT correct regarding Transmissibility ($$T$$)?
A
$$T$$ is nearly unity at small excitation frequencies
B
$$T$$ can be always reduced by using higher damping at any excitation frequency
C
$$T$$ is unity at the frequency ratio of $$\sqrt 2$$
D
$$T$$ is infinity at resonance for undamped systems
GATE ME Subjects
Engineering Mechanics
Machine Design
Strength of Materials
Heat Transfer
Production Engineering
Industrial Engineering
Turbo Machinery
Theory of Machines
Engineering Mathematics
Fluid Mechanics
Thermodynamics
General Aptitude
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