Practice C.3 Wave phenomena with authentic IB Physics exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like mechanics, thermodynamics, and waves. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
A string of length is fixed at both ends and supports standing waves. The wave speed is .
Derive an expression for the wavelength of the harmonic on the string.
In a pipe that is closed at one end and open at the other, only certain harmonics are observed. Explain why some harmonics are missing in such a tube.
Calculate the frequency of the fourth harmonic for the string.
Sketch the standing wave pattern corresponding to the second and fourth harmonic on the string.
Compare the harmonic series for a string fixed at both ends and a pipe closed at one end. Sketch for (d): Second harmonic: 1 full wavelength → 3 nodes, 2 antinodes Fourth harmonic: 2 full wavelengths → 5 nodes, 4 antinodes
A guitar string vibrates in its first harmonic.
State the number of antinodes and nodes present.
State the relationship between the string length and the wavelength .
State the type of wave that travels along the string.
State whether energy is transferred by a standing wave.
A plane wave strikes a boundary between air and water.
Define the term “refraction”.
State what happens to the speed of light as it enters water from air.
Identify whether the wavelength increases or decreases in water.
Suggest why the wave changes direction at the boundary.
A string of length is fixed at both ends and supports a standing wave pattern with three antinodes when under tension. The wave speed on the string is .
State the harmonic number of this standing wave.
Calculate the wavelength of the wave on the string.
Calculate the frequency of the wave.
Sketch the standing wave pattern on the string, showing all nodes and antinodes.
The tension in the string is increased. Explain the effect this has on the frequency of the standing wave, assuming the harmonic number stays the same.
The standing wave in a closed tube resonates at 256 Hz.
Define resonance.
Explain how resonance occurs in a closed air column.
If the tube length is 0.34 m and speed of sound is 340 m/s, calculate the frequency of the next harmonic.
A diffraction grating with 5000 lines/cm is used to measure the wavelength of light.
Convert the line spacing into metres.
Light produces a second-order maximum at . Calculate the wavelength.
State the maximum possible order that could be observed.
A pipe open at both ends produces a standing sound wave.
Draw the fundamental mode.
State the distance between adjacent nodes.
If the pipe is 0.85 m long, calculate the wavelength of the first harmonic.
Calculate the fundamental frequency if the speed of sound is 340 m/s.
A ray of light enters a transparent block from air at an angle of incidence of .
Define the term “refractive index”.
State the equation that relates angle of incidence and refraction.
Calculate the angle of refraction in glass of refractive index .
An open-open pipe resonates with two successive resonant frequencies: and . Assume the speed of sound in air is .
Explain how these frequencies correspond to harmonics in an open-open pipe.
Determine the fundamental frequency of the pipe.
Calculate the length of the pipe.
Sketch the standing wave patterns for the first and third harmonic in an open-open pipe.
A similar pipe is closed at one end. Compare the harmonic series of this pipe with that of the open-open pipe. Sketch description for (d): First harmonic: single loop, antinodes at both ends, one node in the center. Third harmonic: three loops, four antinodes, three nodes evenly spaced along the pipe.
A student wants to determine the speed of electromagnetic waves inside a microwave oven. They remove the rotating plate and place a flat slab of chocolate on the base of the oven. After heating for a few seconds, the chocolate begins to melt at fixed points. The frequency of the microwave is printed on the back of the oven: .
Explain how standing waves are formed inside the microwave oven and why they result in specific points of heating.
Describe how the student could use the melted chocolate to determine the wavelength of the microwave radiation.
The student observes that the distance between melted regions is . Calculate the speed of the microwave radiation in air.
State one assumption and one source of uncertainty in this experiment.
Explain why this experiment does not work with the rotating plate.
In a second attempt, the student forgets to remove the rotating platform. After running the microwave, the entire chocolate slab melts uniformly. Explain why this occurred and why it prevents determining the speed of microwaves.