Electric current is the rate at which charge passes a point: I = Q/t, in amperes — one coulomb per second. Drag the two sliders below to set the charge and the time, and watch the dot stream, the current readout and the electron count respond together.
The charge slider sets how much charge Q crosses the wire's marked cross-section, and the time slider sets how long the crossing takes. The big readout divides one by the other in real time — I = Q/t — so every slider position is a small worked example. Push Q up with t fixed and the current climbs in proportion; the dot stream through the wire quickens to match. The same arithmetic, with the rearrangements for charge and time, runs in the electric current calculator.
The live electron count is the humbling part: N = Q/e turns even a modest charge into billions of billions of electrons. Ten coulombs is about 6.24 × 10^19 of them, each carrying a scarcely believable 1.602 × 10^-19 coulombs. The count sits beside a second figure — electrons per second, I/e — which is the current re-expressed as raw traffic past the plane.
Now hold Q fixed and stretch the time instead. The electron count does not move — the same charge still makes the trip — but the flow visibly thins and the current readout falls. That contrast is the misconception this lab exists to correct: a bigger current is faster charge delivery, not "more electrons existing". Current is a rate, like litres per minute through a pipe, and the cross-section plane in the canvas is exactly the point where the counting happens.
It solves I = Q/t live: you set how much charge Q flows and how long it takes t, and the readout returns the current in amperes together with the electron count. The dot stream in the wire is a visual sample whose speed scales with the current, so a bigger I literally looks like faster delivery past the marked cross-section.
It is N = Q/e — the number of electrons making up the charge you chose, using the elementary charge e = 1.602 x 10^-19 C. Even the minimum 0.1 C is over six hundred million billion electrons, which is why the sim displays the count in scientific notation. It depends only on Q, so stretching the time leaves it untouched.
Because the same charge spread over more seconds is a lower rate, and current is a rate: I = Q/t. Hold Q at 10 C and drag t from 5 s to 50 s — the current drops from 2 A to 0.2 A and the dot flow visibly thins, even though exactly the same number of electrons makes the trip.
Coulombs for charge, seconds for time and amperes for the current — one ampere is one coulomb per second, so the three lock together through I = Q/t. Small results switch to milliamperes for readability, and the electron figures are dimensionless counts shown in scientific notation.
No. This lab uses the charge-flow definition of current, I = Q/t, which involves no circuit at all — just charge and time. Ohm's law, V = IR, predicts how much current a given voltage pushes through a given resistance. Use this sim to understand what current is, and an Ohm's law tool to find its value in a circuit.