Instrumentation Transducers

Seismic Displacement Transducers

Question 1
Marks : +2 | -2
Pass Ratio : 25%
Relative displacement between housing frame and seismic mass in seismic transducer will be ____________
Xi(t)-Xm(t)
Xi(t)+Xm(t)
2Xi(t)
2Xm(t)
Explanation:
Relative displacement between housing frame and seismic mass is the difference between absolute displacement of platform and displacement of mass.
Question 2
Marks : +2 | -2
Pass Ratio : 25%
Which of the following represents the correct relation for undamped natural frequency of system?
KM
(KM)1/2
K/M
(K/M)1/2
Explanation:
Undamped natural frequency of a seismic transducer is the square root of the ratio of restoring force and mass.
Question 3
Marks : +2 | -2
Pass Ratio : 25%
Seismic mass has freedom to move any direction.
True
False
Explanation:
Movement of seismic mass is limited to one direction using a spring and damper system.
Question 4
Marks : +2 | -2
Pass Ratio : 25%
Seismic transducers are used to measure ______________
Displacement
Velocity
Acceleration
All of the mentioned
Explanation:
Seismic transducers can be used to measure small displacement like vibrations, velocity and acceleration.
Question 5
Marks : +2 | -2
Pass Ratio : 25%
How bandwidth can be increased?
Lowering natural frequency
Increasing natural frequency
Doubling natural frequency
Bandwidth cannot be increased
Explanation:
Natural frequency can be lowered for increasing bandwidth of seismic displacement transducer. Which means spring must be softer and mass should be large.
Question 6
Marks : +2 | -2
Pass Ratio : 25%
Seismic transducer is only applicable for displacement measurement.
True
False
Explanation:
Seismic transducers can be used to measure both displacement, velocity and acceleration with several changes on the mass-spring-damper system.
Question 7
Marks : +2 | -2
Pass Ratio : 25%
Which of the following spring-mass arrangement is used for displacement measurement?
Soft spring small mass
Soft spring large mass
Stiff spring small mass
Stiff spring large mass
Explanation:
For displacement measurement, Soft spring large mass arrangement is used. Only in this arrangement, observable changes in the position of mass can be detected.
Question 8
Marks : +2 | -2
Pass Ratio : 25%
Damper system is used to ______________
Produce oscillations
Limit oscillations
To produce displacement
For indication
Explanation:
Damper systems are used to limit oscillations made by mass when the device is displaced.
Question 9
Marks : +2 | -2
Pass Ratio : 25%
Seismic displacement transducers are not suitable for measuring ______________
Vibrating velocities
Static velocities
Dynamic velocities
None of the mentioned
Explanation:
In amplitude response for zero and infinite frequencies amplitude becomes zero and we don’t get any flat amplitude response.
Question 10
Marks : +2 | -2
Pass Ratio : 25%
Which of the following represents the application of spring?
To provide stability
To provide oscillatory motion
To provide restoring force
None of the mentioned
Explanation:
Spring is used to provide restoring force to mass when device displaces.