J
/dzei/
Học thuậtThân thiện
Definition
- Noun:
- The tenth letter of the modern English alphabet: "j" is a consonant, representing a specific speech sound.
- A unit of electrical energy (joule): In physics, "j" is the standard abbreviation for the joule, a derived unit of energy.
Usage Examples
- Noun (Letter):
- The word "jump" starts with the letter "j".
- In the alphabet, "i" comes before "j".
- Noun (Unit):
- The energy required is 5 j. (Note: In formal writing, the unit is typically capitalized as "J" for joule).
- One calorie is approximately 4.184 j.
Advanced Usage
- In mathematics: "j" can be used to represent a variable or an index, particularly in sequences (e.g., ).
- The sum is calculated for j ranging from 1 to 10.
- In engineering and physics: Lowercase "j" can represent the imaginary unit (√-1), especially in electrical engineering to avoid confusion with the symbol for current (i).
- The impedance is expressed as a complex number, 3 + 4j ohms.
Variants and Related Words
- J (noun): The uppercase form of the letter.
- The logo features a large, stylized "J".
- Joule (noun): The full name of the unit of energy abbreviated as "J".
- A joule is defined as a newton-meter.
Synonyms
- Joule: (for the unit of energy) There is no direct synonym for the letter itself.
Related Phrases
- Dot the j's and cross the t's: (Idiom) To be meticulous and pay attention to every small detail.
- Before submitting the report, make sure to dot the j's and cross the t's.
- J-bend: (Technical term) A pipe or tube shaped like the letter "J".
- The sink's drainpipe has a J-bend to prevent sewer gases from entering.
Related Idioms
- Mind your p's and q's: (A related idiom about being careful with details, though it uses different letters).
- When meeting the CEO, remember to mind your p's and q's.
Noun
- the 10th letter of the Roman alphabet
- a unit of electrical energy equal to the work done when a current of one ampere passes through a resistance of one ohm for one second