Component comparisons
The pairs that get mixed up in exams and on the bench, answered side by side rather than in two tabs.
Each page puts the two parts' specs, variants, selection notes and failure modes in matching columns, then says what the choice actually turns on. Every figure is the same one on the component's own reference page, so the two cannot drift apart.
16 comparisons
Linear Regulator vs Switching RegulatorA linear regulator burns the difference between input and output as heat, which makes it simple, quiet and cheap but wasteful.Thermistor vs Thermocouple & RTDA thermistor is cheap and very sensitive over a narrow band, an RTD is linear and accurate, and a thermocouple covers by far the widest range of the three.Fuse vs Resettable Fuse (PTC)A fuse opens once and is replaced, which is exactly why it is the definite protection: near-zero resistance in normal use and an unambiguous break on fault.Photoresistor (LDR) vs PhotodiodeAn LDR is a resistor that changes value with light — cheap, easy, and entirely adequate for deciding whether it is dark yet.MCB vs RCCBThese are not alternatives, and treating them as such is the mistake worth avoiding: they protect different things.Relay vs Solid-State Relay (SSR)An electromechanical relay gives you a genuine air gap, essentially zero on-resistance, and it shrugs off inrush — but the contacts wear, it is slow, and it clicks.Ceramic vs Tantalum CapacitorCeramic (MLCC) is the cheapest, smallest and best-behaved at high frequency — but a class-2 dielectric can lose a large fraction of its rated capacitance under DC bias, which catches people out badly in small packages.Ceramic vs Film CapacitorCeramic wins on size and price and is the default for decoupling.Lead-Acid vs Lithium BatteryLead-acid is cheap per amp-hour, tolerates float charging indefinitely, and is recycled everywhere — but it is heavy, and repeatedly taking it below about half discharged kills it.Choke vs Ferrite BeadThe distinction that matters: a ferrite bead is specified in ohms at a frequency, not in henries.MOSFET vs BJTA BJT is current-driven: hold base current and it conducts, with a roughly fixed saturation drop that does not improve however big the device is.Stepper Motor vs Servo MotorA stepper moves in fixed increments and holds position without any feedback, which makes it simple and genuinely precise at low speed — but it draws full current standing still, loses torque as it speeds up, and if it is overloaded it skips steps silently, so your position is quietly wrong with nothing to tell you.MCB vs MCCBAn MCB protects final circuits up to about 100 A with a fixed, letter-coded trip curve; an MCCB handles hundreds to thousands of amps with an adjustable one.MOSFET vs JFETA JFET's gate is a reverse-biased junction, so it conducts with zero gate voltage and is pinched off by driving the gate the other way — it is normally-on, and the gate must never be forward-biased.Fuse vs MCBA fuse is a wire that melts: cheap, very fast on a hard short circuit, and gone once it has operated.Optocoupler vs Solid-State RelayAn optocoupler is the isolation barrier on its own — an LED shining at a phototransistor, good for a signal of a few milliamps.