ACOUSTIC AND ELECTRICAL PROPERTIES OF WOOD Flashcards

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1
Q
  • is in relation to sound or it
    refers to its capacity to absorb
    or reflect sound and reduce
    vibrations
A

Acoustic Property

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2
Q
  • ability to absorb and prevent
    reflections of sound
A

Acoustic Property

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3
Q
  • has a high damping capacity;
    therefore, it is an ideal material
    for structural components in
    which vibration is unwanted
A

Acoustic Property

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4
Q

WOOD IS ACOUSTIC:

A
  1. Presence of pores, vessel lines, and microcapillaries
  2. Fabricated holes
  3. Fabricated striations
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5
Q

_________ wood is effective as a sound-absorbing material because it exhibits a small specific impedance (Smardzewski et al. (2014)

A

high porosity

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6
Q

__________ is essential in the design and construction of musical
instruments, The placement, size, and shape of these holes
influence the resonance, tone, volume, and overall acoustic
performance of the instrument

A

fabricated holes

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7
Q

__________ is a craftsmanship of the instrument, including how the wood is treated, shaped, and assembled, also plays a significant
role in determining the final sound.

A

fabricated striations

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8
Q

SOFTWOOD has a _____ sound absorption at high frequencies;
effective in reducing echoes and
_____ sound reflection;
better for diffusing sound.

A

high; moderate

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9
Q

HARDWOOD has a ____ sound absorption overall; absorbs less high-frequency sound and ____ sound reflection especially at lower frequencies.

A

lower; high

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10
Q

_______ are better in reflecting soundwaves

A

denser wood

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11
Q

_______ are sustain and creates more sharp tone

A

hardwood

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12
Q

______ are less sustain and has a softer tones

A

softwood

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13
Q
  • Unit used to measure sound, named after Alexander Graham
    Bell
A

DECIBEL

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14
Q

______ decibel is the normal level for human.

A

60-70

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15
Q

_____ is the maximum for safe volume level for ears.

A

80 dB

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16
Q

_____ for breathing and _____ for whisper

A

10 dB; 15 dB

17
Q
  • Capacity of wood to withstand induced vibration by sound waves transmitted from the outside forces
A

RESONANCE OF WOOD

18
Q
  • Deals with the movement or flow of energy in the form of electric
    charge such as electrons.
A

ELECTRICAL PROPERTIES OF WOOD

19
Q

Movement of electricity can be classified in two different ways:

A
  1. Direct Current (DC) and
  2. Alternating Current (AC)
20
Q
  • flow of electric charge in one direction.
A

Direct Current (DC)

21
Q
  • flow of electric charge that frequently reverses direction.
A

Alternating Current (AC)

22
Q

DIRECT CURRENT (DC) ELECTRICAL
PROPERTIES OF WOOD:

A

a. Resistivity
b. Conductivity

23
Q
  • exhibits how strongly it resists the flow of electric current.
A

Resistivity

24
Q
  • as the MC of wood increases from ovendry to FSP, resistivity decreases.
A

Resistivity

25
Q
  • as the MC continue to increase from FSP to complete MC saturation in wood, the
    smaller its electrical resistivity (Glass,et al., 2010)
A

Resistivity

26
Q

high MOISTURE CONTENT, low RESISTIVITY (vice versa)

A

low MOISTURE CONTENT, high RESISTIVITY

27
Q

– reciprocal of electrical resistivity.

A

Conductivity

28
Q
  • wood’s ability to conduct electric current.
A

Conductivity

29
Q
  • electrical conductivity of wood increases as temperature increases unlike the conductivity of metal.
A

Conductivity

30
Q
  • the wood conductivity is greater along the grain direction compared to the direction across the grain,
    and greater in the radial section than in the tangential section (Glass, et.al., 2010).
A

Conductivity

31
Q

The AC electrical properties of wood deals with the _____
constant.

A

dielectric

32
Q
  • also known as relative permittivity
A

Dielectric Constant

33
Q
  • is defined as the ratio of the permittivity of a substance to the permittivity of free space
A

Dielectric Constant

34
Q

The dielectric constant of wood is basically the __________________ stored in wood in the form of electric polarization when the material is in a given electric field

A

measure of energy per unit volume

35
Q

FACTORS AFFECTING ELECTRICAL
PROPERTIES OF WOOD:

A
  1. Moisture Content
  2. Temperature
  3. Wood Type
  4. Grain Orientation