FREE Physics Waves and Optics Questions and Answers
What is the wavelength of a wave traveling at 300 m/s with a frequency of 150 Hz?
Correct!
Wrong!
The relationship between wave speed (𝑣), wavelength (λ), and frequency (𝑓) is given by: v=fλ. Rearrange to solve for 𝜆: 𝜆=𝑣/𝑓=300m/s/150Hz=2 m. λ=v/ f = 300m/s/150Hz=2m.
Which of the following is an example of a longitudinal wave?
Correct!
Wrong!
Longitudinal waves are characterized by particle oscillations parallel to the direction of wave propagation. Sound waves are a classic example, as air particles vibrate along the direction the wave travels.
When light passes from air into glass, which of the following occurs?
Correct!
Wrong!
As light enters a denser medium like glass, its speed decreases. Since frequency remains constant, the wavelength must also decrease, as given by 𝑣=𝑓𝜆.
What is the angle of refraction when light enters water (refractive index n=1.33) from air at an angle of 30°? (Use Snell's Law: n 1sinθ 1 =n 2sinθ 2).
Correct!
Wrong!
Snell’s Law: 𝑛1sin𝜃1=𝑛2sin𝜃2. θ 2 =arcsin(0.376)≈22.1 ∘ .
A slit experiment produces a bright fringe 3 mm away from the central maximum on a screen 2 m away. If the slit separation is 0.5mm, what is the wavelength of light used?
Correct!
Wrong!
The formula for the fringe position in a double-slit experiment is: 𝑦=𝑚𝜆𝐿/𝑑, λ= y⋅d/m⋅L = 0.003⋅0.0005/1⋅2=0.0000005m=500nm.