NSAA NSAA Physics - Waves and Optics

Question 1

A wave has a frequency of 5 Hz and a wavelength of 4 m. What is its speed?

Accepted Answer

20 m/s

Answer

Wave speed v = fλ = 5 × 4 = 20 m/s.

Question 2

Which type of wave requires a medium to travel through?

Accepted Answer

Mechanical waves

Answer

Mechanical waves, such as sound, require a physical medium to propagate.

Question 3

A light ray passes from air into glass and bends toward the normal. This is because in glass the light:

Accepted Answer

Travels slower

Answer

Light slows down when entering a denser medium, causing refraction toward the normal.

Question 4

What is the period of a wave with frequency 50 Hz?

Accepted Answer

0.02 s

Answer

Period T = 1/f = 1/50 = 0.02 s.

Question 5

In the double-slit experiment, constructive interference occurs when the path difference between the two sources is:

Accepted Answer

Any multiple of λ

Answer

Constructive interference occurs when path difference = nλ (n = 0, 1, 2, ...), so waves arrive in phase.

NSAA - Natural Sciences Admissions Assessment Practice Test