MULTIMETER LAB

volts, amps, ohms — and where the probes actually go

- - -

place both probes

RED probenot placed

BLACK probenot placed

Circuit powerOFF

Battery voltage 9 V

Circuit power: OFF

Ohm's Law: V = I × R I = V / R R = V / I

Same math, on a physical calculator

C4× — V = I × R: know current and resistance, multiply to get voltage

D4÷ — I = V / R: know voltage and resistance, divide to get current

D4÷ — R = V / I: same key, flip which number goes on top, to get resistance

A4+ — resistors in series (like R1 and R2 here) just add straight across

The one rule per mode

Voltmeter → parallel

Touch two points without breaking anything.
High internal resistance — barely any current flows through the meter itself.
Safe to touch across any two points, circuit on or off.

Ammeter → series

Must become part of the current's actual path — break the wire, meter completes the loop.
Near-zero internal resistance — touched across two points like a voltmeter, it's a dead short.
That mistake blows the meter's fuse in real life. Every time.

Ohmmeter → power OFF

The meter supplies its own tiny test current to measure resistance.
An outside voltage source fighting that test current gives a false reading — or damages the meter.
Always de-energize the circuit first.

Reading this schematic

These four symbols are standard — the same ones on any real circuit diagram, any datasheet, any textbook. Learn to read them here and they transfer everywhere, not just in this simulator.

Session Log Entry — what this Wrap Up wrote to the Ledger

— click Wrap Up to log this session —