Physical Constants
Each with its value
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This deck costs you nothing. You get 22 flashcards, sorted into 4 categories and with notes that add to them. You start out learning instead of typing, and whatever you find missing later you add yourself.
- Cards
- 22
- Categories
- 4
- Price
- free
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What is in this deck
With this deck you learn 22 physical constants with their values: from the speed of light to the elementary charge.
Since 2019 the speed of light is no longer measured. It is fixed, and the metre depends on it, not the other way round.
This deck asks 22 constants with value and unit. For the seven that carry the SI system, the note says they are exact and which unit hangs on them. For the gravitational constant it says the opposite: it is the least precisely known of them all.
Values follow CODATA as published by NIST.
The categories decide what comes up: start with “Electromagnetism” alone and add the rest when you are ready.
What you learn
- 22 constants with value and unit
- Which seven have been exact since 2019
- Why the kilogram no longer needs a cylinder
The categories
4 categories sort the 22 cards. You can filter by category and take on what is due right now.
- Electromagnetism
- Fundamental
- Particles and atoms
- Thermodynamics
What you get
Here are three of the 22 cards that are in this deck.
Question
What is the value of the speed of light in vacuum?
Answer
299 792 458 m/s
Note
Fixed exactly. Since 1983 the metre is defined through this number, not the other way round.
Question
What is the value of the Planck constant?
Answer
6,626 070 15 × 10⁻³⁴ J s
Note
Fixed exactly. Since 2019 the kilogram depends on it, the prototype cylinder is retired.
Question
What is the value of the elementary charge?
Answer
1,602 176 634 × 10⁻¹⁹ C
Note
Fixed exactly since the 2019 SI revision. It is no longer measured.
Learning with Qardbox
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This deck costs nothing. Its 22 cards are checked and save you the work you would otherwise have.
Common questions
Do I have to pay for Qardbox?
No. The app is free, with no subscription and no ads, and every function is there. This deck is free too; some other ready-made decks cost a little, once.
Could I make these cards myself?
Yes, without limit and for free. You can type them, import a file or take over cards from friends. This deck only saves you the work.
How many cards are in Physical Constants?
22 cards, sorted into 4 categories.
Do I need a connection to study?
Only to download the deck. After that it lives on your device and you study offline. There is no account, and you sign in nowhere.
Which devices does this run on?
On iPhone and iPad from iOS 26, and on Apple Watch. One purchase covers the family through Family Sharing.
Is there a Qardbox for Android?
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Other decks that go with this one
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