ASVAB CampCircuit Components and Symbols flashcards
8 cards with the formulas, rules and traps from this lesson. Answer in your head, then flip to check.
Fact · 1/8
Cell symbol: which plate is the positive terminal?
The longer line is positive; the shorter (often thicker) line is negative. One long-short pair is a single cell; repeated pairs show a multi-cell battery.
Rule · 2/8
On a schematic, do two lines that cross without a dot connect?
Under the usual convention, no: a plain crossing passes over like an overpass. A solid dot marks a real junction where all touching lines form one node. Follow any stated legend.
Term · 3/8
Electrically, what do 'open' and 'closed' mean for a switch?
Open means the contacts are apart and no current passes. Closed means the contacts touch and the switch acts like a wire. Closed completes the circuit (opposite of a water valve).
Fact · 4/8
Diode symbol: which side is the cathode, and which way does current flow?
The triangle points toward the bar; the bar is the cathode (marked by a band on the real part). Conventional current flows easily from anode to cathode when forward biased.
Fact · 5/8
How do the LED and photodiode symbols differ?
Both are a diode triangle and bar. An LED has small arrows pointing outward (light emitted); a photodiode has arrows pointing inward (light received).
Fact · 6/8
Capacitor versus inductor symbols and units?
A capacitor is two equal parallel plates (C, farads) and stores energy in an electric field. An inductor is a row of loops (L, henries) and stores energy in a magnetic field.
Term · 7/8
Fuse versus circuit breaker?
Both open the circuit on overcurrent and go in series with what they protect. A fuse's link melts and must be replaced with the same rating; a breaker opens a contact and can be reset.
Fact · 8/8
BJT symbol: how do you tell NPN from PNP?
Look at the emitter arrow. Pointing out of the symbol means NPN ('not pointing in'); pointing in means PNP. Terminals are emitter, base and collector, labeled Q.