Description : High noise levels produced during operation of fans and compressors can be reduced by using (A) Mufflers (silencers) (B) Acoustic absorbent (C) Lagging of noisy duct (D) None of these
Last Answer : (A) Mufflers (silencers)
Description : Ability of a material to __________ is indicated by its damping capacity. (A) Withstand compression (B) Absorb vibration (C) Absorb shock (D) None of these
Last Answer : (B) Absorb vibration
Description : 'Green House Effect' means - (1) cultivation of crops in green house to conserve heat (2) trapping of solar energy due to carbon dioxide gases (3) trapping of solar energy by earth upper surface (4) increase of heat due to atmospheric pollution
Last Answer : (2) trapping of solar energy due to carbon dioxide gases Explanation: Green House Effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases and is re-radiated in all directions.
Description : Green House Effect' means (1) Pollution in houses in tropical region (2) Prevention of ultraviolet radiation by the ozone layer (3) Trapping of solar energy due to atmospheric gases (4) Damage to green painted buildings
Last Answer : (3) Trapping of solar energy due to atmospheric gases Explanation: The greenhouse effect occurs when Earth's atmosphere traps solar radiation because of the presence of certain gases, causing the ... , nitrous oxide (N2O) and other gases, ac-cording to the Environmental Protection Agency (EPA
Description : Green House Effect’ means (1) Pollution in houses in tropical region (2) Prevention of ultraviolet radiation by the ozone layer (3) Trapping of solar energy due to atmospheric gases (4) Damage to green painted buildings
Last Answer : Trapping of solar energy due to atmospheric gases
Description : ‘Green House Effect’ means (1) cultivation of crops in green house to conserve heat (2) trapping of solar energy due to carbon dioxide gases (3) trapping of solar energy by earth upper surface (4) increase of heat due to atmospheric pollution
Last Answer : trapping of solar energy due to carbon dioxide gases
Description : where springs of low damping are required for the purpose of vibration isolation, it will be most desirable to use A) Metallic springs B) Rubber pad C) Air springs D) Neoprene pads
Last Answer : A) Metallic springs
Description : In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be A less than unity B equal to unity C greater than unity D zero
Last Answer : C greater than unity
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as A Damping factor B Damping coefficient C Logarithmic decrement D Magnification factor
Last Answer : D Magnification factor
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots. A 25.62 rad/sec B 20.78 rad/sec C 14.4 rad/sec D 15.33 rad/sec
Last Answer : A 25.62 rad/sec
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots. A 21 rad/sec B 25.62 rad/sec C 20.22 Hz D 3.15 Hz
Last Answer : B 25.62 rad/sec
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force is known as A Logarithmic decrement B Magnification factor C Damping factor D None of the mentioned
Last Answer : B Magnification factor
Description : In coulomb damping the frequency of damped vibrations is A Equal to that of undamped vibrations B Less than that of undamped vibrationsC More than that of undamped vibrations D Independent of the frequency of undamped vibration
Last Answer : A Equal to that of undamped vibrations
Description : Natural frequency of the system is due to A Resonance B Forced Vibration C Damping D Free Vibration
Last Answer : D Free Vibration
Description : In vibration isolation system, the transmissibility will be equal to unity, for all values of damping factor, if ω/ωn is A. Equal to 1 B. Equal to √2 C. Less than √2 D. Greater than √2
Last Answer : B. Equal to √2
Description : If frequency of excitation of a forced vibration system with negligible damping is very close to natural frequency of the system, then the system will A) Execute harmonic motion of large amplitude B) Beat with a very high peak amplitude C) Perform aperiodic motion D) None of the above
Last Answer : A) Execute harmonic motion of large amplitude
Description : If ωmax is the frequency at which the peak amplitude occurs and ωn is the natural frequency of the system then In a forced vibration system with damping, the higher the damping, A) More will be ... and ωmax is independent of damping in this system D) The difference between ωn and ωmax will be zero
Last Answer : A) More will be the difference between ωn and ωmax
Description : In the case of steady state forced vibration at a resonance, the amplitude of vibration is A) Inversely proportional to damping coefficient B) Inversely proportional to damping ratio C) Inversely proportional to resonant frequency D) Directly proportional to resonant frequency
Last Answer : B) Inversely proportional to damping ratio
Description : In case of viscous damping the frequency of damped vibration is A) Equal to that of undamped vibrations B) Less than that of undamped vibrations C) Greater than that of undamped vibrations D) Independent than that of undamped vibrations
Last Answer : B) Less than that of undamped vibrations
Description : Natural frequency of the system is due to A) Free vibration B) Forced vibration C) Resonance D) Damping
Last Answer : A) Free vibration
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and A natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots. ( A )25.62 rad/sec ( B )20.78 rad/sec ( C )14.4 rad/sec ( D )15.33 rad/sec
Last Answer : ( A )25.62 rad/sec
Description : The vibrations can be controlled by A. Controlling the natural frequencies B. Using proper damping devices C. Introducing vibration absorbers and vibration isolators D. All the above
Last Answer : D. All the above
Description : The ratio of maximum displacement of the forced vibration to the deflection due to the static force, is known as A. Damping FactorB. Damping Coefficient C. Logarithmic Decrement D. Magnification Factor
Last Answer : D. Magnification Factor
Description : The advantage of critical damping is A. That vibrating body come to rest in smallest possible time B. There is no vibration C. That amplitude of vibration is maximum D. The amplitude of vibration is minimum
Last Answer : A. That vibrating body come to rest in smallest possible time
Description : In vibration isolation system, if ω/ω n < 2, then for all values of damping factor, the transmissibility will be a) less than unity b) equal to unity c) greater than unity d) zero
Last Answer : c) greater than unity
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequ the system is 30 rad/sec which consists of machine supported on springs and dashpots. a. 25.62 rad/secb. 20.78 rad/sec c. 14.4 rad/sec d. 15.33 rad/sec
Last Answer : a. 25.62 rad/sec
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as a) Damping factor b) Damping coefficient c) Logarithmic decrement d) Magnification factor
Last Answer : d) Magnification factor
Description : Reduction in vibration amplitude after one complete cycle of single degree free vibration with dry friction damping is_____, if where F"= frictional force between mass and surface and k =stiffness of the system. a)4F/k a b) 2f/K C) 3F/k D)8F/k
Last Answer : a)4F/k
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force is known as (A) damping factor (B) damping coefficient (C) logarithmic decrement (D) magnification factor
Last Answer : (D) magnification factor
Description : n vibration isolation system, if ω/ω n is less than √2 , then for all values of the damping factor, the transmissibility will be a) less than unity b) equal to unity c) greater than unity d) zero
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as a) damping factor b) damping coefficient c) logarithmic decrement d) magnification factor
Last Answer : d) magnification factor
Description : For controlling the vibration of the disc of ac energy meter, damping torque is produced by
Last Answer : For controlling the vibration of the disc of ac energy meter, damping torque is produced by Eddy current
Description : Green Revolution of 1960s was associated with: (a) use of HYV seeds (b) tree plantation programme (c) fisheries development (d) None of these
Last Answer : (a) use of HYV seeds
Description : Boring question #78; sonics aka silencers are they that quiet really or does size matter?
Last Answer : The mythbusters did an episode on that recently. “Silencers” do not make gun shots quiet. Just a bit less loud.
Description : trans-acting factors include (A) Promoters (B) Repressors (C) Enhancers (D) Silencers
Last Answer : Answer : B
Description : cis-acting elements include (A) Steroid hormones (B) Calcitriol (C) Histones (D) Silencers
Last Answer : Answer : D
Description : Ringelmann chart is used for the evaluation of __________ pollution. (A) Air (B) Water (C) Noise (D) Radioactive
Last Answer : (A) Air
Description : What are the measures to control noise pollution? -Geography
Last Answer : 1. Industries must be located away from the residential areas. 2. Construction of sound proof walls in the factories. 3. Restricting unnecessary use of sirens, horns and loud speakers. 4. ... 5. Protective instruments the workers in the industries. 6. Noise producing vehicles must be checked.
Description : In which year Air (Prevention and Control of Pollution) Act was amended to include noise as an air pollutant?
Last Answer : In which year Air (Prevention and Control of Pollution) Act was amended to include noise as an air pollutant? A. 1972 B. 1981 C. 1987 D. 1990
Last Answer : In which year Air (Prevention and Control of Pollution) Act was amended to include noise as an air pollutant ... . Noise C. Water D. None of the above
Description : Electrostatic precipitator is used to control the pollution of – (1) air (2) water (3) noise (4) thermal
Last Answer : (1) air Explanation: An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an ... particles from a flowing gas (such as air) using the force of an induced electrostatic charge.
Description : Electrostatic precipitator is used to control — (1) Air pollution (2) Water pollution (3) Solid waste (4) Noise pollution
Last Answer : (1) Air pollution Explanation: An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force ... , and can easily remove fine particulate matter such as dust and smoke from the air stream.
Description : Electrostatic precipitator is used to control – (1) Air pollution (2) Water pollution (3) Solid waste (4) Noise pollution
Last Answer : Air pollution
Description : Electrostatic precipitator is used to control the pollution of (1) air (2) water (3) noise (4) thermal
Last Answer : air
Description : Which of the following methods should be used to test for an 'open' coil in an AC motor stator? A. Test with an ohmmeter, one test lead on the shaft, and the other test lead to the stator leads ... an open coil. D. Use a growler, listening for noise and vibration to increase when over an open coil.
Last Answer : Answer: B
Description : What will a noise vibration analysis show me?
Last Answer : A noise vibration analysis will show you exactly what is wrong in the motor of you car. It basically pin points where the noise is coming from by the vibrations and it will tell you what part is bad by how far away the part is.
Description : A testing device called a 'growler' is being used to locate a shorted coil in the stator of an AC electrical machine. When the 'feeler' is moved over a slot containing the shorted coil _____________. ... . the meter needle will be deflected to zero D. the meter needle will be deflected to full-scale
Last Answer : Answer: A
Description : A shading coil used in an AC magnetic controller, functions to _____________. A. reduce vibration and noise in the contactor B. prevent flux buildup in the operating coil C. eliminate arcing when the contacts close D. energize the operating coil and 'pull in' the contacts
Description : Following is advantage of hyperbolic design a) Less initial cost b) Less noise c) Less vibration d) All above
Last Answer : b) Less noise