Title: Class 8 physics sound
Question : 1
Two waves of the same pitch have amplitudes in the ratio 1 : 3. Find the ratio of
(i) loudness
(ii) pitch
Solution:
(i)Ratio of Loudness
(Loudness of sound is directly proportional to square of amplitude of wave)
L ∝ (A)²
Step 1: Write amplitude ratio
A₁ : A₂ = 1 : 3
Step 2: Square each amplitude
A₁² : A₂² = (1)² : (3)²
=1:9
Step 3: Loudness ratio
L₁ : L₂ = 1 : 9
(ii) Ratio of Pitch
Since both waves have same pitch,
Pitch₁ = Pitch₂
When two quantities are equal,
their ratio is 1 : 1
Therefore:
Pitch₁ : Pitch₂ = 1 : 1
Final Answer:
(i) Loudness ratio = 1 : 9
(ii) Pitch ratio = 1 : 1
Question : 1
Two waves of the same pitch have amplitudes in the ratio 1 : 3. Find the ratio of
(i) loudness
(ii) pitch
Solution:
(i)Ratio of Loudness
(Loudness of sound is directly proportional to square of amplitude of wave)
L ∝ (A)²
Step 1: Write amplitude ratio
A₁ : A₂ = 1 : 3
Step 2: Square each amplitude
A₁² : A₂² = (1)² : (3)²
=1:9
Step 3: Loudness ratio
L₁ : L₂ = 1 : 9
(ii) Ratio of Pitch
Since both waves have same pitch,
Pitch₁ = Pitch₂
When two quantities are equal,
their ratio is 1 : 1
Therefore:
Pitch₁ : Pitch₂ = 1 : 1
Final Answer:
(i) Loudness ratio = 1 : 9
(ii) Pitch ratio = 1 : 1
