architectural acoustics & superconductivity

8/12/2019 Architectural Acoustics & Superconductivity

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PHYSICS ACTIVE LEARNING ASSESSMEN

Name Enrollment No:-

Deep Patel 130410107064

Dhruvi Patel 130410107066

Jayan Patel 130410107068

Poojan Patel 130410107070

Raj Patel 130410107072


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Reverberation is the persistence or prolongation of sound in a hall even aftestopped emitting sound.

The Reverberation time is the time taken by sound to fall below the minimumlevel.

REMEDIES:-

By Providing windows and openings. By having full capacity of audience in hall or room. By using heavy curtains with folds. By covering the floor with carpets. By decorating walls with beautiful pictures, poster, maps, etc. By covering the ceiling and wall with good sound absorbing materials like

fiberboard false roofing etc.


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The uniform distribution of loudness in hall or a room is an important factor fohearing. Sometime, the loudness may get reduced due to excess of sound-amaterials used inside hall or room.

REMEDIES:-

By using suitable absorbent at places where noise is high. As a result, thedistribution of loudness may become uniform.

By constructing low ceilings for the reflection of sound towards the listener By using large sounding boards behind the speakers and facing the audie By using public address system like loudspeaker.


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The presence of any concave surface or any other curved surface in the hamay make the sound to be concentrated at this focus region. As a result, thenot be heard at all other regions. These regions are referred as dead space. surfaces must be avoided.

REMEDIES:-

Curved surfaces can be avoided. If curved surface are present, they shoucovered with suitable sound absorbing materials.


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An echo is heard due to reflection of sound from a distant sound-reflecting o

REMEDIES:-

An echo can be avoided by covering long-distance walls and high ceilinsuitable sound-absorbing materials, This prevents reflection of sound.


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It refers to generation of new separate sound due multiple echoes. A set of rregular reflecting surface is said to produce the echelon effect. This echelonaffects the quality of the original sound.

REMEDIES:-

The remedy to avoid echelon effect is to cover such surface with sound-amaterials.


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Resonance occurs due to matching frequency. If the windows panels and swooden portions have not tightly fitted, they may start vibrating, there by crextra sound in addition to the sound produced in the hall.

REMEDIES:-

The resonance may be avoided by fixing the windows panels properly. Anvibrating object which may produce resonance can be placed over a susound-absorbing materials.


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REMEDIES:- The hall or room can be made air conditioned. The sound can be eliminated by using double walls with air space betwee By using curtains for sound absorbing.

The unwanted sound is called noise. The Hall or room should be properly insuexternal and internal noises.There are three types of noise:-

1. Air-borne noise:- Extraneous noise which are coming from outside.2. Structure-borne noise:- The noise which is conveyed through the structure

building.3. Inside noise:- The noise which are produced inside the hall or room.


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5. Magnetic field effect

The minimum magnetic field required to destroy tsuper conducting state is called the critical magnefield HcHc=H[1-(T/Tc)]

where His critical field at 0 k.


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6. Critical current density : it can be define as the maximumcurrent that can be permitted in a superconducting materia

without destroying its superconducting state. It is function of temperature.

7. Persistent current : the steady flow of current in asuperconducting ring with out any potential deriving it icalled the persistent current .


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Type -1 superconductor Type -2 superconductor


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These superconductor arecalled as softsuperconductor.

These superconductor arecalled as hardsuperconductor

The critical field value is very

low.

The critical field value is very

high.Exhibits the perfect &complete meissner effect.

Do not exhibit a perfect &complete meissner effect.


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Low temperature superconductor

Superconductor that require liquid helium as coolant are called

low temperature superconductor

High temperature superconductor

Superconductor having their Tc values above the temperature

of liquid nitrogen are called the high temperaturesuperconductor.


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CRYOTRON:


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architectural acoustics & superconductivity

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