levo

Waves

Harmonics and the fundamental mode

  • 3 things to know
  • Papers 2 and 3

Overview

Recall questions on the fundamental and the higher harmonics, and on the frequencies at which they occur.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Numbers

For the fundamental mode of a stretched string, describe the pattern of nodes and antinodes and state the relationship between string length and wavelength.

Numbers

For a closed tube, describe the node and antinode arrangement and the relationship between tube length and wavelength in the fundamental mode, and state which harmonics it can produce.

Numbers

For an open tube, describe the node and antinode arrangement and the relationship between tube length and wavelength in the fundamental mode, and state which harmonics it can produce.

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    State the relationship between string length and wavelength for the fundamental mode of a stretched string.

    Model answer

    The string length equals half a wavelength (L = λ/2).

  2. 2

    Describe the node and antinode arrangement in the fundamental mode of a closed tube.

    Model answer

    One node at the closed end and one antinode at the open end.

  3. 3

    State the relationship between tube length and wavelength for the fundamental mode of a closed tube.

    Model answer

    The tube length equals one quarter of a wavelength (L = λ/4).

  4. 4

    Which harmonics can a closed tube produce?

    Model answer

    A closed tube can only produce odd harmonics (1st, 3rd, 5th, etc.).

  5. 5

    Describe the node and antinode arrangement in the fundamental mode of an open tube.

    Model answer

    Antinodes at both ends and one node in the centre.

  6. 6

    State the relationship between tube length and wavelength for the fundamental mode of an open tube.

    Model answer

    The tube length equals half a wavelength (L = λ/2).

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Practical Skills in the Written Papers
The Practical Endorsement
Physical Quantities and Units
Making Measurements and Analysing Data

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

A wave.
longitudinaltransversestationary

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AForce is a vector quantity.
BDistance is a scalar quantity.
CVelocity is a vector quantity.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Density means mass per unit volume.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Waves, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.