Practice Quiz: Waves in Physics Worksheet

This option correctly defines a wave as a disturbance that propagates energy without the net movement of matter. The other choices introduce inaccuracies regarding the nature and behavior of waves.

Wavelength is defined as the spatial period of the wave, which is the distance between corresponding points such as crest to crest or trough to trough. This distinguishes it from other wave properties like period or amplitude.

Frequency is the measure of how many complete cycles a wave undergoes in a unit of time, usually seconds. This distinguishes it from properties such as wavelength or amplitude.

The speed of a wave on a string is largely determined by the tension in the string as well as its mass per unit length. Increasing the tension generally results in a higher wave speed.

The energy transmitted by a wave is generally proportional to the square of its amplitude. Higher amplitude waves carry more energy, making amplitude a key indicator of energy content.

The correct relationship between wave speed, frequency, and wavelength is given by v = f × λ. This equation shows that the product of the frequency and the wavelength equals the wave's speed.

Refraction is the phenomenon where a wave changes direction as it passes from one medium to another. This bending occurs due to a change in the wave's speed within the new medium.

When a wave transitions between different media, its frequency remains constant while the speed and wavelength may change. This is due to the requirement that the source's frequency is preserved across the boundary.

The Doppler Effect arises from the relative motion between the source and the observer. This motion leads to a perceived change in the frequency (and wavelength) of the wave, distinguishing it from changes in amplitude or direction.

Constructive interference occurs when two waves are in phase, meaning their peaks and troughs align, thereby combining to produce a wave of greater amplitude. The other options do not lead to reinforcement of the wave signal.

A node in a standing wave is a point where destructive interference causes the medium to remain stationary. It is characterized by zero amplitude, distinguishing it from antinodes where the amplitude is at its maximum.

Increasing the tension on a rope increases the wave speed because the wave travels faster when the medium is stretched tighter. The mass per unit length also plays a role, but the tension is the key factor in this context.

Intensity measures the energy transmitted per unit area per unit time by a wave. It is directly related to the square of the amplitude, making it a key indicator of a wave's energy transfer rate.

Diffraction is the bending of waves around obstacles and openings, which becomes more noticeable when the size of the obstacle is comparable to the wavelength. The other phenomena relate to different wave behaviors and do not account for this bending effect.

The pitch of a sound is primarily determined by its frequency, with higher frequencies corresponding to higher pitches. Amplitude, on the other hand, largely affects the loudness and not the pitch.

For a string fixed at both ends, the nth harmonic has (n+1) nodes and n antinodes. In the third harmonic mode, this gives four nodes and three antinodes, making the second option correct.

When a wave moves from one medium to another while maintaining its frequency, any change in speed results in a proportional change in wavelength. Since sound travels faster in water than in air, its wavelength increases.

Since intensity is proportional to the square of the amplitude, tripling the amplitude results in an increase in intensity by a factor of 3², which is 9. This shows how energy changes nonlinearly with amplitude.

The beat frequency is equal to the absolute difference between the frequencies of the two interfering waves. Hence, hearing two beats per second indicates a frequency difference of 2 Hz.

In the function y(x, t) = A sin(kx - ωt), the negative sign before ωt indicates that as time increases, the phase remains constant only if x increases. This means that the wave propagates in the positive x-direction.