PHYSICS

JAMB 2002 - Question 13

Physics 2002 JAMB Past Questions - Question 13: I. Temperature II. Density of air molecules. III. Pressure. IV. Pitch. Which of the above will affect the velocity of sound in air?

I. Temperature II. Density of air molecules. III. Pressure. IV. Pitch. Which of the above will affect the velocity of sound in air?
A:
B:
C:
D:
Examkits App

Examkit's JAMB CBT App

Practice JAMB offline with our Online, PC and Mobile App

  • ✅ 25+ years of past questions (2000 to 2025)
  • ✅ Video solutions and explanation to questions
  • ✅ E-library
  • ✅ Study by topic
  • ✅ And more.

Correct Answer

D

Explanation

The velocity of sound in air is primarily affected by temperature. Here's how each of the factors you listed relates to the velocity of sound:

I. Temperature: Temperature has a significant impact on the speed of sound in air. In general, sound travels faster in warmer air and slower in colder air. The relationship between the speed of sound (v), temperature (T), and absolute temperature (in Kelvin) is described by the following formula:

v = √(γ * R * T)

Where:
- v is the speed of sound.
- γ (gamma) is the adiabatic index or the ratio of specific heats for dry air, which is approximately 1.4.
- R is the specific gas constant for dry air.
- T is the absolute temperature in Kelvin.

II. Density of air molecules: The density of air molecules can influence the speed of sound indirectly through its relationship with temperature. As temperature increases, air becomes less dense, and sound tends to travel faster. Conversely, lower temperatures result in denser air and slower sound propagation. So, while density is a factor, it is closely linked to temperature.

III. Pressure: Pressure, by itself, does not significantly affect the velocity of sound in air. Sound travels through air as pressure waves, but variations in pressure alone do not cause significant changes in the speed of sound. The primary factors that influence the speed of sound in air are temperature and, to some extent, humidity.

IV. Pitch: Pitch refers to the perceived frequency of a sound and is not a direct factor affecting the speed of sound in air. Pitch is related to the frequency of the sound wave, and the frequency can influence the characteristics of a sound, but it does not directly affect the speed at which sound travels through the air.

In summary, temperature is the primary factor affecting the velocity of sound in air, while the other factors you mentioned (density, pressure, and pitch) are not direct factors influencing sound speed.