Sound Test

Result

Sound Test - 46

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

The speed of a sound wave is $$340\;ms^{-1}$$. What is the wavelength of the wave if its frequency is $$500\;Hz$$ ?

A
$$0.68\;m$$

B
$$6.8\;m$$

C
$$68\;m$$

D
$$0.068\;m$$

Solution

Given: Speed of the sound wave $$=340\, ms^{-1}$$
Frequency $$=500\,Hz$$

We have the equation,

$$\text{Wavelength}=\dfrac{\text{Speed of the wave}}{\text{Frequency}}$$

Substituting the values we get,

$$ \text{Wavelength}=\dfrac{340}{500}=0.68\,m$$

Hence the wavelength of the sound wave is $$0.68\,m$$.
Question 2
1 / -0

The time period of a vibrating body is $$0.01\;sec$$. Its frequency will be :

A
$$1.0\;s^{-1}$$

B
$$10.0\;s^{-1}$$

C
$$100.0\;s^{-1}$$

D
$$1000.0\;s^{-1}$$

Solution

Given,
Time period $$=0.01\,sec$$
We have to find the frequency.
We have the relation, $$Frequency=\dfrac{1}{Time\,Period}$$
$$\therefore Frequency=\dfrac{1}{0.01}=100\,s^{-1}$$
Question 3
1 / -0

A normal man is unable to hear the sound emitted by source. Out of the possible reasons, the one which is not applicable is

A
The pitch of the sound may be too high

B
The pitch of the sound may be too low

C
The quality of the sound is not matching with the man's requirement

D
The amplitude of sound may be too small

Solution
Question 4
1 / -0

Sound waves cannot pass through

A
a solid-liquid mixture

B
an ideal gas

C
a liquid-gas mixture

D
a pefect vacuum

Solution

Sound cannot travel through a perfect vacuum. A vacuum is a space without any medium. Sound requires a material medium for its propagation, and hence 'Sound waves cannot pass through a perfect vacuum.'
Question 5
1 / -0

A sound wave completes $$20$$ vibrations in $$2.5\;s$$. Its frequency will be equal to :

A
$$20\;Hz$$

B
$$8\;Hz$$

C
$$200\;Hz$$

D
$$50\;Hz$$

Solution

We have,

$$Frequency=\frac{Number\,of\,vibration}{Time\,taken}$$

It is given that the sound wave completes 20 vibrations in 2.5 seconds

Hence,

$$Frequency=\frac{20}{2.5}=8\,Hz$$
Question 6
1 / -0

The product of the time period of a sound wave and its frequency is equal to:

A
infinite

B
zero

C
more than unity but less than infinity

D
unity

Solution

We have the equation,

$$f=\frac{1}{T}$$

where,

$$f$$ is the frequency

$$T$$ is the time period

Hence the product of the time period of the sound wave and its frequency is equal to unity.
Question 7
1 / -0

Imagine a cannon being fired on the surface of the moon. Then

A
the sound will be heard at the surface of the earth during all seasons

B
the sound will not be heard at the surface of the earth

C
the sound will be heard at the surface of the earth during the rainy season

D
no sound will be heard on the earth or on the moon

Solution

Sound waves need a material medium to propagate. Since there is no atmosphere on the moon, so sound cannot propagate in space and hence no sound will be heard at the surface of the earth as well as on the moon.
Question 8
1 / -0

The echo will be heard if the orginal sound reflected by an obstacle reaches our ears after

A
$$10 sec$$`

B
$$5 sec$$

C
$$1 sec$$

D
$$0.1 sec$$

Solution

As the sensation of sound persists in our brain for about 0.1 second, to hear a distinct echo the time interval between the original sound and the reflected one must be at least 0.1 second.
Question 9
1 / -0

The frequency of sound waves is $$11\ kHz$$ and its wavelength is $$20\ cm$$, then the velocity of sound waves is ______.

A
$$220\ {ms}^{-1}$$

B
$$220\ cm {s}^{-1}$$

C
$$2200\ cm {s}^{-1}$$

D
$$2200\ {ms}^{-1}$$

Solution

Given,
Frequency, $$ f= 11 \times 10^{3}\ Hz$$
Wavelength, $$\lambda = 20\ cm=0.2\ m$$
Velocity of sound wave, $$v$$

We know,
$$ v =f \times \lambda$$
$$v= 11 \times 10^{3} \times 0.2$$
$$v =2200\ m/s$$
Question 10
1 / -0

An echo will be heard if the minimum distance between the source of sound and the obstacle is

A
1 m

B
10 m

C
15 m

D
17 m

Solution

As the sensation of sound persists in our brain for about 0.1 s, to hear a distinct echo the time interval between the original sound and the reflected one must be at least 0.1s. If we take the speed of sound to be 344 m/s at a given temperature, say at 22 ºC in air, sound must go to the obstacle and reach back the ear of the listener on reflection after 0.1s.

Hence, the total distance covered by the sound from the point of generation to the reflecting surface and back should be at least (344 m/s) ×0.1 s = 34.4 m. Thus, for hearing distinct echoes, the minimum distance of the obstacle from the source of sound must be half of this distance. I.e., 34.4/2 = 17 m.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Sound Test - 46

Result

Sound Test - 46

Score

-

Rank

-

SHARING IS CARING

Question 1

$$0.68\;m$$

$$6.8\;m$$

$$68\;m$$

$$0.068\;m$$

Solution

Question 2

$$1.0\;s^{-1}$$

$$10.0\;s^{-1}$$

$$100.0\;s^{-1}$$

$$1000.0\;s^{-1}$$

Solution

Question 3

The pitch of the sound may be too high

The pitch of the sound may be too low

The quality of the sound is not matching with the man's requirement

The amplitude of sound may be too small

Solution

Question 4

a solid-liquid mixture

an ideal gas

a liquid-gas mixture

a pefect vacuum

Solution

Question 5

$$20\;Hz$$

$$8\;Hz$$

$$200\;Hz$$

$$50\;Hz$$

Solution

Question 6

infinite

zero

more than unity but less than infinity

unity

Solution

Question 7

the sound will be heard at the surface of the earth during all seasons

the sound will not be heard at the surface of the earth

the sound will be heard at the surface of the earth during the rainy season

no sound will be heard on the earth or on the moon

Solution

Question 8

$$10 sec$$`

$$5 sec$$

$$1 sec$$

$$0.1 sec$$

Solution

Question 9

$$220\ {ms}^{-1}$$

$$220\ cm {s}^{-1}$$

$$2200\ cm {s}^{-1}$$

$$2200\ {ms}^{-1}$$

Solution

Question 10

1 m

10 m

15 m

17 m

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.