Hearing Quiz 1

Question 1

A sound wave is travelling through a medium such that at $${{200}^{\circ }}	ext{ C}$$ the velocity of the sound is $${{v}_{0}}$$. What is the change in velocity if temperature increases by $${{200}^{\circ }}	ext{ C}$$?

Accepted Answer

$$0.19{{v}_{0}}$$

Answer

$$0.91{{v}_{0}}$$

Answer

$${{v}_{0}}$$

Answer

None of the above

Question 2

The velocity of wind is $$420	ext{ m}{{	ext{s}}^{-1}}$$ and the velocity of the sound travelling through it is $$330	ext{ m}{{	ext{s}}^{-1}}$$ . Calculate the angle between the direction of the wind and the direction of the sound propagation. Assume the effective velocity of the sound to be $$400\,	ext{m}{{	ext{s}}^{-1}}$$

Accepted Answer

$${{\cos }^{-1}}\left( \dfrac{-179}{396} \right)$$

Answer

$${{\cos }^{-1}}\left( \dfrac{149}{476} \right)$$

Answer

$${{\cos }^{-1}}\left( \dfrac{217}{896} \right)$$

Answer

None of the above

Question 3

A sound is travelling in a medium such that this medium is full of a gas with $$\gamma =\dfrac{3}{2}$$. If the pressure is $$2	ext{ bar}$$ at $${{273}^{\circ }}	ext{ K}$$ . Calculate the velocity of the sound. Take the volume of the medium as $$100	ext{ L}$$ and the mass of the gas as $$129	ext{ g}$$.

Accepted Answer

$$1.53	ext{ m}{{	ext{s}}^{-1}}$$

Answer

$$1.69	ext{ m}{{	ext{s}}^{-1}}$$

Answer

$$1.45	ext{ m}{{	ext{s}}^{-1}}$$

Answer

None of the above.

Question 4

A man is producing a sound of pressure amplitude as $$1.97	imes {{10}^{-5}}	ext{ N}{{	ext{m}}^{-2}}$$. Does this sound audible to the man? Take the density of the medium to be $$1.2	ext{ kg}{{	ext{m}}^{-3}}$$ and velocity of the sound is $$343	ext{ m}{{	ext{s}}^{-1}}$$.

Accepted Answer

No, the sound is not audible to the man

Answer

The sound is audible but it is very loud.

Answer

The sound is audible but it is very faint.

Answer

Yes, the sound is audible to the man.

Question 5

A point source emits a sound wave in a spherical form. The output power is $$60	ext{ W}$$.Calculate the energy where the intensity of the sound will be $$1.47	imes {{10}^{-6}}	ext{ W}{{	ext{m}}^{2}}$$. Assume the speed of the sound wave to be $$330	ext{ m}{{	ext{s}}^{-2}}$$.

Accepted Answer

$$1802.24	ext{ m}$$

Answer

$$1782.25	ext{ m}$$

Answer

$$1648.25	ext{ m}$$

Answer

None of the above