Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 806 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.🔋 How many 1.5 V cells must be joined in series to give 7.5 V?
2. 2.⏱️ A program says “wait 1250 ms”. How many seconds is that? =
3. 3.True or false: a diode smooths a wobbly supply. (a) False (b) True
4. 4.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
5. 5.⚡ What does a water heater mainly change electricity into? (a) light (b) sound (c) movement (d) heat
6. 6.True or false: the voltmeter measures current. (a) False (b) True
7. 7.Which of these is the input? (a) check if temp > 30 (b) a buzzer beeps (c) an LED lights up (d) a light level reading
8. 8.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
9. 9.Which of these uses electricity? (a) a generator (b) a washing machine (c) a battery (d) a power station
10. 10.🔍 Which is the odd one out? (a) an exhaust fan (b) a ceiling fan (c) a table fan (d) an electric kettle
11. 11.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I + R (c) V = R ÷ I (d) V = I × R
12. 12.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) straight lines (c) wavy lines (d) dotted circles
13. 13.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) ask a parent first (b) post it online (c) share it with friends (d) type it all in
14. 14.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
15. 15.What does a potentiometer do? (a) is a resistance knob (b) lets current go one way (c) glows using little power (d) senses how hot it is
16. 16.⏱️ How many milliseconds is a wait of 5 seconds?
17. 17.⚡ A cell changes stored chemical energy into which kind of energy? (a) electrical energy (b) sound energy (c) nuclear energy (d) wind energy
18. 18.True or false: aluminium foil is an insulator. (a) True (b) False
19. 19.True or false: to share only needed data is a risky habit. (a) False (b) True
20. 20.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a buzzer (c) a resistor (d) a diode
21. 21.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) switch (b) junction (c) capacitor (d) resistor
22. 22.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to an 8 V supply. What current flows (in mA)?
23. 23.🔌 Is a motor an input or an output for a microcontroller? (a) output (b) input
24. 24.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 9600 Ω resistor? (a) white-blue-orange (b) white-blue-brown (c) blue-white-red (d) white-blue-red
25. 25.Which of these is a good habit? (a) share the Wi-Fi key (b) reuse one password (c) accept every permission (d) read app permissions
26. 26.💡 A battery lights 5 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
27. 27.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber band across the gap. Does the bulb glow? (a) Yes (b) No
28. 28.🔍 Which sensor would you use to measure classroom noise? (a) a light sensor (b) a sound sensor (c) a temperature sensor (d) a gas sensor
29. 29.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
30. 30.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) mute it when not in use (b) tell it your passwords (c) put it in the bathroom (d) let strangers use it
31. 31.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) wire (b) battery (c) cell (d) diode
32. 32.Which of these is true of a series circuit? (a) one out, the rest glow (b) many paths for current (c) own switch for each bulb (d) a break stops every bulb
33. 33.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 5 is taken out of its holder. How many bulbs glow?
34. 34.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they get dimmer (c) they explode (d) they keep glowing
35. 35.🔺 A current of 0.2 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
36. 36.True or false: current is measured in watts (W). (a) False (b) True
37. 37.📏 Which unit measures how much a part resists? (a) ohm (Ω) (b) watt (W) (c) ampere (A) (d) volt (V)
38. 38.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
39. 39.⚡ A device works on 3 V and takes 1.5 A. What is its power (in watts)? =
40. 40.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 15 %. What happens? (a) pump ON (b) pump OFF

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