IB Physics SL C.2 Wave model Question Bank

Practise extracting wave quantities from diagrams or graphs, applying the wave equation and connecting particle motion, energy transfer and wave type.

Exam points

extract amplitude, wavelength, period or frequency from graphs and calculate wave speed with v=fλ
distinguish transverse and longitudinal waves using particle motion, propagation and compressions
explain travelling-wave energy transfer and calculate intensity, attenuation or amplitude changes
use c for electromagnetic waves in vacuum to calculate frequency, wavelength or signal travel time

Covered syllabus points

C.2.1—Wave energy transfer C.2.2—Wave quantities C.2.3—Wave equation C.2.4—Transverse and longitudinal waves C.2.5—Electromagnetic wave speed

[Maximum number: 4]

(a)

Outline what is meant by a travelling wave.

[ 2 ]

(b)

A loudspeaker emits sound of frequency 210 Hz into a pipe with one open and one closed end. The diagram shows a representation of the standing wave established in the pipe.

[ 2 ]

(i)

Calculate the speed of sound in the pipe stating the answer to an appropriate number of significant figures.

[ 2 ]

$c=\ll \lambda f=1.60 \times 210 \Rightarrow \gg 336$ OR $340 \ll \mathrm{~m} \mathrm{~s}^{-1} \gg$
Any answer to 2 OR 3 s.f.

Marking guidance:

Allow ECF from incorrect wavelength in
bii)

[2]

[Maximum number: 6]

This question is in two parts. Part 1 is about the nuclear model of the atom and radioactive decay. Part 2 is about waves.

Part 1 Nuclear model of the atom and radioactive decay

(a)

State the amplitude of wave A.

[ 1 ]

5 mm or 5.0 mm ; units are required Allow other units, eg: $5 / 5.0 \times 10^{-3} \mathrm{~m}$ .

(b)

Wave A has a frequency of 9.0 Hz . Calculate the velocity of wave A .

[ 2 ]

wavelength $=8.0 \mathrm{~cm}$ or 8 cm ; (accept clear substitution in MP2 for this mark) $v=(f \lambda=) 9 \times 8=72 \mathrm{~cm} \mathrm{~s}^{-1}$ ; units are required

(c)

Deduce the frequency of wave B.

[ 3 ]

wavelength $=3.9 \mathrm{~cm}$ ; (accept answers in the range of 3.8 to 4.0 cm )
frequency $=\left(\frac{72}{3.9}=\right) 18$ ;
Hz or $\mathrm{s}^{-1}$ ;

[Maximum number: 4]

This question is in two parts. Part 1 is about a thermistor circuit. Part 2 is about vibrations and waves.
Part 1 Thermistor circuit
The circuit shows a negative temperature coefficient (NTC) thermistor X and a $100 \mathrm{k} \Omega$ fixed resistor R connected across a battery.

Figure for Question C.2 Wave model question 3 — IB Physics SL

The battery has an electromotive force (emf) of 12.0 V and negligible internal resistance.

(a)

The sound waves from the loudspeaker travel in air with speed $330 \mathrm{~m} \mathrm{~s}^{-1}$ .

[ 4 ]

(i)

Calculate the wavelength of the sound waves.

[ 1 ]

(ii)

Describe the characteristics of sound waves in air.

[ 3 ]

All question bank results loaded

Covered syllabus points

C.2 Wave model question 1

Question (a)

Question (b)

Question (i)

C.2 Wave model question 2

Question (a)

Question (b)

Question (c)

C.2 Wave model question 3

Question (a)

Question (i)

Question (ii)