Waves Sound and Light Practice Questions
Matric (South Africa) · Matric Physical Sciences · 145 free MCQs with instant results and detailed explanations.
145
Total
42
Easy
80
Medium
23
Hard
Start Practicing Waves Sound and Light
Take a timed quiz or customize your practice session
Sample Questions from Waves Sound and Light
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the speed of sound in air at room temperature (20°C)?
A.
343 m/s
B.
300 m/s
C.
1500 m/s
D.
600 m/s
Show Answer & Explanation
Correct Answer: A
The speed of sound in air at room temperature is approximately 343 m/s. This is a well-known value used in various physics applications.
Q2
Easy
Which of the following best describes a longitudinal wave?
A.
The particles move perpendicular to the wave direction.
B.
The particles move parallel to the wave direction.
C.
The wave has a fixed frequency.
D.
The wave travels faster in vacuum than in air.
Show Answer & Explanation
Correct Answer: B
In a longitudinal wave, particles of the medium move parallel to the direction of the wave's travel, creating compressions and rarefactions.
Q3
Easy
What is the speed of sound in air at room temperature (20°C)?
A.
343 m/s
B.
300 m/s
C.
1500 m/s
D.
1200 m/s
Show Answer & Explanation
Correct Answer: A
The speed of sound in air at room temperature is approximately 343 m/s. This value is determined by factors such as the medium and its temperature, and at 20°C, it is typically around this figure.
Q4
Medium
What is the frequency of a sound wave if its wavelength is 0.5 meters and the speed of sound in air is 340 m/s?
A.
680 Hz
B.
340 Hz
C.
170 Hz
D.
850 Hz
Show Answer & Explanation
Correct Answer: A
Frequency is calculated using the formula f = v / λ. Here, v = 340 m/s and λ = 0.5 m, so f = 340 / 0.5 = 680 Hz.
Q5
Medium
A tuning fork produces a sound wave of 512 Hz. What is the time period of this sound wave?
A.
0.002 seconds
B.
0.004 seconds
C.
0.008 seconds
D.
0.016 seconds
Show Answer & Explanation
Correct Answer: B
The time period (T) is the reciprocal of frequency (f): T = 1/f. Hence, T = 1/512 = 0.001953 seconds, which rounds to 0.004 seconds.
Q6
Medium
Which of the following phenomena explains why we see a rainbow after rain?
A.
Reflection
B.
Refraction
C.
Diffraction
D.
Interference
Show Answer & Explanation
Correct Answer: B
A rainbow is formed due to the refraction, reflection, and dispersion of light in water droplets, resulting in a spectrum of colors.
Q7
Medium
If the sound intensity level is increased by 10 dB, how does the intensity of the sound change?
A.
Doubles
B.
Increases by a factor of 10
C.
Increases by a factor of 100
D.
Increases by a factor of 20
Show Answer & Explanation
Correct Answer: C
An increase of 10 dB corresponds to a tenfold increase in intensity. Thus, going from I to 10I results in a factor of 100 increase.
Q8
Hard
A sound wave travels through air at a speed of 343 m/s. If the frequency of the sound wave is 256 Hz, what is the wavelength of the sound wave?
A.
1.34 m
B.
0.77 m
C.
0.86 m
D.
1.02 m
Show Answer & Explanation
Correct Answer: A
Wavelength (λ) can be calculated using the formula λ = v/f, where v is the speed of sound and f is the frequency. Substituting the values, λ = 343 m/s / 256 Hz = 1.34 m.
Q9
Hard
Two tuning forks are struck, one at 440 Hz and the other at 450 Hz. What is the beat frequency produced by these two tuning forks?
A.
10 Hz
B.
5 Hz
C.
20 Hz
D.
15 Hz
Show Answer & Explanation
Correct Answer: A
The beat frequency is calculated by finding the absolute difference between the frequencies of the two sound waves. Here, |450 Hz - 440 Hz| = 10 Hz, which is the beat frequency.
Q10
Hard
A sound wave travels through air at a speed of 343 m/s. If the frequency of the sound wave is 256 Hz, what is the wavelength of the sound wave?
A.
1.34 m
B.
0.5 m
C.
0.75 m
D.
1.5 m
Show Answer & Explanation
Correct Answer: A
The wavelength (λ) of a wave can be calculated using the formula λ = v/f, where v is the speed of the wave, and f is the frequency. Here, λ = 343 m/s / 256 Hz = 1.34 m. Thus, option A is correct.
Showing 10 of 145 questions. Start a quiz to practice all questions with scoring and timer.
Practice All 145 Questions →More Matric Physical Sciences Chapters
Other Matric (South Africa) Subjects
Waves Sound and Light — Matric (South Africa) Matric Physical Sciences Practice Questions Online
This page contains 145 practice MCQs for the chapter Waves Sound and Light in Matric (South Africa) Matric Physical Sciences. The questions are organized by difficulty — 42 easy, 80 medium, 23 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.