A whole sentence includes a subject and a predicate
Warm air rises causing an area of lower air pressure below.
The statement is false.
Pitch of a sound wave is the quantity that determines how high or low a sound is when it is perceived. A higher pitch corresponds to a higher frequency.
There could be another case, the Doppler's effect. the source or the observer might be moving towards the other. In such cases, the frequency of the sound wave does not change but it appears to be rising due to the motion.
Complete Question:
A hollow cylinder with an inner radius of 4.0mm and an outer radius of 30mm conducts a 3.0-A current flowing parallel to the axis of the cylinder. If the current density is uniform throughout the wire, what is the magnitude of the magnetic field at a point 12mm from its center?
Answer:
The magnitude of the magnetic field = 7.24 μT
Explanation:
Inner radius, a = 4.0 mm = 0.004 m
Outer radius, b = 30 mm = 0.03 m
Radius, r = 12 mm = 0.012 m
let h² = b² - a²
h² = 0.03² - 0.004²
h² = 0.000884
Let d² = r² - a²
d² = 0.012² - 0.004²
d² = 0.000128
Current I = 3A
μ = 4π * 10⁻⁷
The magnitude of the magnetic field is given by:

B = 7.24 * 10⁻⁶T
B = 7.24 μT