PHYS 112 EXAM 3 |250 MULTIPLE CHOICE
QUESTIONS WITH CORRECT ANSWERS AND
DETAILED RATIONALES
SECTION 1: WAVES AND SOUND (Questions 1–50)
1. A wave has a frequency of 50 Hz and a wavelength of 2.0 m. What is its
wave speed?
A) 25 m/s
B) 50 m/s
C) 100 m/s
D) 150 m/s
E) 200 m/s
Correct Answer: C — Wave speed v = fλ = (50 Hz)(2.0 m) = 100 m/s.
2. The time required for one complete wave cycle is called the:
A) Frequency
B) Wavelength
C) Period
D) Amplitude
,E) Speed
Correct Answer: C — The period (T) is the time for one complete cycle,
inversely related to frequency (T = 1/f).
3. Which type of wave requires a medium to travel through?
A) Radio waves
B) Light waves
C) Mechanical waves
D) Xrays
E) Gamma rays
Correct Answer: C — Mechanical waves (sound, water waves, seismic waves)
require a medium. Electromagnetic waves do not.
4. The distance between two consecutive crests of a wave is the:
A) Amplitude
B) Frequency
C) Period
D) Wavelength
E) Speed
,Correct Answer: D — Wavelength (λ) is the distance between successive
crests or troughs.
5. A sound wave has a frequency of 440 Hz. What is its period?
A) 0.00227 s
B) 0.00454 s
C) 0.00909 s
D) 0.0182 s
E) 0.0364 s
Correct Answer: A — T = 1/f = 1/440 = 0.00227 s.
6. The maximum displacement of a particle from its equilibrium position is
the:
A) Wavelength
B) Frequency
C) Amplitude
D) Period
E) Speed
Correct Answer: C — Amplitude is the maximum displacement from
equilibrium.
, 7. Which of the following waves is longitudinal?
A) Light wave
B) Radio wave
C) Sound wave
D) Water wave
E) Xray
Correct Answer: C — Sound waves are longitudinal (particles oscillate parallel
to wave direction). Light and radio waves are transverse.
8. The speed of sound is fastest in:
A) Air
B) Water
C) Steel
D) Vacuum
E) Helium
Correct Answer: C — Sound travels fastest in solids (steel) due to higher
elasticity and density.
QUESTIONS WITH CORRECT ANSWERS AND
DETAILED RATIONALES
SECTION 1: WAVES AND SOUND (Questions 1–50)
1. A wave has a frequency of 50 Hz and a wavelength of 2.0 m. What is its
wave speed?
A) 25 m/s
B) 50 m/s
C) 100 m/s
D) 150 m/s
E) 200 m/s
Correct Answer: C — Wave speed v = fλ = (50 Hz)(2.0 m) = 100 m/s.
2. The time required for one complete wave cycle is called the:
A) Frequency
B) Wavelength
C) Period
D) Amplitude
,E) Speed
Correct Answer: C — The period (T) is the time for one complete cycle,
inversely related to frequency (T = 1/f).
3. Which type of wave requires a medium to travel through?
A) Radio waves
B) Light waves
C) Mechanical waves
D) Xrays
E) Gamma rays
Correct Answer: C — Mechanical waves (sound, water waves, seismic waves)
require a medium. Electromagnetic waves do not.
4. The distance between two consecutive crests of a wave is the:
A) Amplitude
B) Frequency
C) Period
D) Wavelength
E) Speed
,Correct Answer: D — Wavelength (λ) is the distance between successive
crests or troughs.
5. A sound wave has a frequency of 440 Hz. What is its period?
A) 0.00227 s
B) 0.00454 s
C) 0.00909 s
D) 0.0182 s
E) 0.0364 s
Correct Answer: A — T = 1/f = 1/440 = 0.00227 s.
6. The maximum displacement of a particle from its equilibrium position is
the:
A) Wavelength
B) Frequency
C) Amplitude
D) Period
E) Speed
Correct Answer: C — Amplitude is the maximum displacement from
equilibrium.
, 7. Which of the following waves is longitudinal?
A) Light wave
B) Radio wave
C) Sound wave
D) Water wave
E) Xray
Correct Answer: C — Sound waves are longitudinal (particles oscillate parallel
to wave direction). Light and radio waves are transverse.
8. The speed of sound is fastest in:
A) Air
B) Water
C) Steel
D) Vacuum
E) Helium
Correct Answer: C — Sound travels fastest in solids (steel) due to higher
elasticity and density.
