Ang resistor The resistor — a traffic jam for electrons

Malalim na aralinDeep dive 3 · high school

Tagalog: draft — for Kate / Janet to check.  Battery = 9 V, red LED ≈ 2 V, resistors rated 0.5 W, as in the source video.

1. Bakit kailangan Why we need one

Walang resistor = sirang LED. Bago o pagkatapos ng LED: pareho lang. No resistor = dead LED. Before or after the LED makes no difference: same current through the whole loop.

2. Sa loob Inside

Mas mahaba at mas manipis na daan = mas mataas na resistance. A longer, thinner path = more resistance. That's what the spiral groove does.

3. Kulay Colour code

0 itim · 1 kayumanggi · 2 pula · 3 kahel · 4 dilaw · 5 berde · 6 asul · 7 lila · 8 abo · 9 puti. Ginto ±5%, pilak ±10%. 4 bands: digit, digit, multiplier, tolerance. 5 bands: three digits, multiplier, tolerance.

4. Init at lakas Heat and power

P = V × I = V² ÷ R. 9 V sa 10 Ω = 8 W, pero 0.5 W lang ang kaya → nasusunog. 9 V across 10 Ω = 8.1 W into a 0.5 W part: it burns.

5. Divider

Vout = V × R2 ÷ (R1 + R2). Two resistors in series split the voltage; in parallel they share the current.

6. Mga kusang nagbabago Ones that change by themselves

Thermistor (init), LDR (liwanag), strain gauge (baluktot). Thermistor: heat. LDR: light (cadmium: the club uses TEMT6000 instead). Strain gauge: bending.