• Pixel-art sticker of Resista, personifying Ohm's Law, with the caption “More Ohms, Less Flow.”

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Resista

Ohm's Law Physics

\[V = IR\]
$4.99 USD
$4.99 USD
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Meet Resista, for whom more ohms means less flow: for an ohmic conductor, current is proportional to voltage, V = IR. At a fixed voltage, more resistance means less current. Pixel-art kiss-cut sticker in 2, 3, 4 and 6 inches; equation, symbols and sources in the physics panel below.

Size
Surface

Flat $6 shipping worldwideMade to order, ships in 2–5 business days

Details

Size3″ × 3″

3″ × 3″ kiss-cut sticker.

Shipping

Flat $6 shipping on every order, worldwide, whatever's in it.

Delivery times & where we ship

Returns & replacements21 days

Every item is printed to order, so we can’t accept returns or exchanges for change of mind, or if you ordered the wrong size or colour.

Print defect, misprint, damage or the wrong item? We’ll send a free replacement, or a refund if you prefer. Report it within 21 days of delivery with a photo; no need to send it back.

Full refund & replacement policy

The physics

Meet Resista, a resistor who decides how much current gets through for each volt.

Georg Ohm published in 1827 that the current through many conductors is proportional to the voltage across them. The ratio is the resistance, R = V/I, measured in ohms. Materials and parts for which R stays constant over a range of voltages are called ohmic.

Example: a 9 volt battery across a 450 ohm resistor drives 9 / 450 = 0.02 amperes, 20 milliamperes. Double the resistance and the current halves. The resistor also turns electrical energy into heat at a rate of VI, here 0.18 watts.

Ohm's law is the starting point of circuit design. Resistors set LED currents, divide voltages for sensors and limit current to protect parts.

Many devices are not ohmic. A diode lets current through mainly one way, and a filament lamp's resistance rises as it heats up. Resistance also changes with temperature for most materials.

Equations

\[V = IR\]
SymbolMeaningUnit
\(V\) voltage across the resistor \(\mathrm{V}\)
\(I\) current \(\mathrm{A}\)
\(R\) resistance \(\mathrm{Ω}\)

Sources

  1. OpenStax University Physics Vol. 2 — Ohm's Law
  2. Wikipedia — Ohm's law

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