EJU EJU Science: Physics - Waves and Electricity 1 — Questions and Answers
Question 1: What is the relationship between wave frequency (f), wavelength (λ), and wave speed (v)?
- v = fλ (Correct answer)
- v = f + λ
- v = f / λ
- v = λ / f
Correct answer: v = fλ
The wave equation v = fλ states that wave speed equals frequency multiplied by wavelength.
Question 2: In the EJU physics context, what phenomenon occurs when two waves overlap and their displacements add together?
- Superposition (Correct answer)
- Refraction
- Diffraction
- Polarization
Correct answer: Superposition
The principle of superposition states that when two waves meet, the resulting displacement is the sum of the individual displacements.
Question 3: A sound wave has a frequency of 500 Hz and travels at 340 m/s in air. What is its wavelength?
- 0.68 m (Correct answer)
- 6.8 m
- 170 m
- 0.068 m
Correct answer: 0.68 m
Using v = fλ, λ = v/f = 340/500 = 0.68 m.
Question 4: What type of wave is sound?
- Longitudinal wave (Correct answer)
- Transverse wave
- Electromagnetic wave
- Standing wave
Correct answer: Longitudinal wave
Sound is a longitudinal wave because the particles in the medium vibrate parallel to the direction of wave propagation.
Question 5: Which of the following correctly describes the Doppler effect?
- The observed frequency of a wave changes when the source or observer is moving (Correct answer)
- Waves bend around obstacles
- Waves bounce off surfaces
- Waves slow down in denser media
Correct answer: The observed frequency of a wave changes when the source or observer is moving
The Doppler effect is the change in observed frequency due to relative motion between the wave source and the observer.
Question 6: What is the unit of frequency in the SI system?
- Hertz (Hz) (Correct answer)
- Joule (J)
- Newton (N)
- Pascal (Pa)
Correct answer: Hertz (Hz)
Frequency is measured in Hertz (Hz), where 1 Hz equals one cycle per second.
EJU EJU Science: Physics - Waves and Electricity 1
What is the relationship between wave frequency (f), wavelength (λ), and wave speed (v)?