Meaning & use
modulus
Last updated
Meanings
nouncountablemathematics
The size of a number or complex number regardless of sign, such as 5 for both 5 and -5, or the length of a complex number's vector.
Grammar: Countable; the plural is moduli.
Patterns
- the modulus of something
The modulus of -7 is 7.
To find the modulus of a complex number, take the square root of the sum of the squares of its parts.
Students must learn to write the modulus of a vector with two vertical bars.
nouncountablemathematics
In modular arithmetic, the fixed number by which values are divided, with only the remainder kept.
Grammar: Countable; often used as in 'modulo' expressions: arithmetic with modulus 12.
Patterns
- modulus of something
- with modulus n
On a clock, the modulus is 12, so 14 o'clock becomes 2.
The code uses a large prime as its modulus.
If the modulus is 5, then 17 and 2 are considered equal.
nouncountablephysicstechnical
In physics and engineering, a number that measures how strongly a material resists being changed in shape under stress.
Grammar: Usually named for the type of deformation: Young's modulus, bulk modulus.
Patterns
- the modulus of something
Steel has a much higher elastic modulus than rubber.
The engineer checked the Young's modulus of the beam material.
A material with a low modulus bends easily under load.
Word forms
| plural | moduli |
|---|
Common combinations
- Young's modulus
- Young's modulus tells us how stiff a material is.
- elastic modulus
- Glass has a high elastic modulus.
- modulus of a complex number
- The modulus of a complex number is its distance from zero.
- bulk modulus
- Water has a large bulk modulus because it resists compression.
- calculate the modulus
- Calculate the modulus of the vector before you normalize it.
Synonyms and how they differ
- absolute value
- Absolute value is the usual term for real numbers, while modulus is more usual for complex numbers and vectors.
- magnitude
- Magnitude is often used for vectors and physical quantities and is wider than modulus.
- stiffness
- Stiffness is an everyday word for resistance to bending, whereas the modulus is a precise measured value.
Word family
Commonly confused: modulus or module?
modulus vs module
A module is a separate unit or course section. A modulus is a mathematical or physical quantity.
Practice
What is the modulus of -9, in the sense of absolute value?
Choose one answer.
The modulus ignores the sign and gives the size, so -9 has modulus 9. Option 81 is the square, not the modulus.
Make it your own
Write a sentence using “modulus”, then check it and compare it with the examples above.