Practice physics class test — Year 4: mechanical waves and sound.
15 questions drawn at random from a bank of 25, on the block of the programme your teacher is finishing: every attempt is a different test. No penalty for wrong answers, so answer even if you are not sure. At the end you receive by email the correct answer to every question and your weak topics — with an account you see them straight away here on the page. The step-by-step solution unlocks with your first lesson.
A class test is the written test an Italian high-school class sits after each block of the programme; this practice version is multiple choice.
Test in ItalianThe questions of this simulator are in Italian, as in the real exam.
Programme covered by the test
- Quantities of a wave and the relation v = λf
- Transverse and longitudinal waves, speed in different media
- Superposition, constructive and destructive interference
- Path difference and beats
- Standing waves on a string and harmonics
- Open and closed organ pipes
- Sound intensity and level in decibels
- The Doppler effect with a moving source or observer
Two worked examples from the test
Su una corda si propaga un'onda di lunghezza d'onda e frequenza .
Con quale velocità viaggia l'onda?
Solution
La relazione fondamentale delle onde periodiche è
Infatti in un periodo l'onda avanza esattamente di una lunghezza d'onda, e in un secondo di periodi ce ne stanno .
Controllo delle unità: metri per hertz, cioè metri per , dà metri al secondo. Se invece si dividesse, come nelle opzioni e , si otterrebbero unità che non sono quelle di una velocità: è il modo più rapido per accorgersi dell'errore.
Un diapason emette un suono di frequenza . Nell'aria il suono viaggia a .
Quanto vale la lunghezza d'onda?
Solution
Da ricavo la lunghezza d'onda:
Mezzo metro: un ordine di grandezza tipico per i suoni udibili, che nell'aria vanno da qualche centimetro (suoni acutissimi) a diversi metri (suoni molto gravi).
Capovolgere la frazione () dà un numero che non è una lunghezza d'onda ma il suo reciproco moltiplicato per : la verifica dimensionale è di nuovo il controllo più rapido.
In the online practice test you will find 13 more questions like these; the correct answer to every question arrives by email.
Prefer paper? Download the test as a PDF (15 questions, 4 pages · 81 KB, ready to print). You receive the solutions by email after taking it online.
Download the PDFWhat a physics test on waves and sound looks like
The relation v = λf applied several times, constructive and destructive interference with the path difference, beats, standing waves on a string or in an organ pipe with the harmonics, sound level in decibels and the Doppler effect.
The mistake that costs the grade
In standing waves, using the formula for the open pipe for the closed one: the closed pipe has only the odd harmonics and a different fundamental wavelength. In the Doppler effect, putting the wrong sign in the denominator depending on whether the source approaches or recedes.
How to use this practice test
Take it once cold, without revising and with the timer on: it is there to show you where you stand, not to look good. Then look at your weak topics, revise only those — usually two or three, not the whole chapter — and retake it after a few days. The 15 questions are drawn from a bank of 25, so the second attempt is not the same test and the scores are genuinely comparable.
Is the score not enough?
See which topics lost you the most marks, then read the typical physics mistakes in high school — or we look at your results together: the diagnostic is free.