Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 803 · 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.True or false: “a knob turned part way” is an analog signal. (a) True (b) False
2. 2.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 25 Ω resistor? (a) red-green-brown (b) red-green-black (c) green-red-black (d) orange-green-black
3. 3.🤖 What is a microcontroller? (a) a big desktop computer (b) a computer on one chip (c) a type of battery (d) a kind of bulb
4. 4.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 10 (c) 100 (d) 60
5. 5.🔍 Which is the odd one out? (a) a metal paper clip (b) a copper wire (c) a ceramic cup (d) a steel spoon
6. 6.🧮 A 22 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
7. 7.Which of these means the circuit is closed? (a) the switch is OFF (b) the loop is complete (c) a wire is cut (d) the bulb is unscrewed
8. 8.💡 4 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
9. 9.🔍 Which is the odd one out? (a) read app permissions (b) install software updates (c) set a strong password (d) tap unknown app links
10. 10.Which of these is measured in ohms (Ω)? (a) the flow of charge (b) power (c) how much a part resists (d) current
11. 11.Which of these usually has a microcontroller inside? (a) a plain wall switch (b) a spinning top (c) a toy robot (d) a hand pump
12. 12.Which drawing is the symbol for a voltmeter? (a) a long and a short line (b) triangle, bar and arrows (c) triangle against a bar (d) a circle with V inside
13. 13.⏱️ How many milliseconds is a wait of 2.2 seconds?
14. 14.Which of these is the output? (a) a soil moisture reading (b) a button press (c) an LED lights up (d) decide if soil is dry
15. 15.🧮 A 0.7 V battery is joined to 3 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
16. 16.True or false: to switch on with a clap, use a rain sensor. (a) True (b) False
17. 17.True or false: to build with an adult near is not safe. (a) True (b) False
18. 18.⚠️ Is it safe to take cells out after use? (a) not safe (b) safe
19. 19.Which of these mainly makes movement? (a) an electric iron (b) a loudspeaker (c) an exhaust fan (d) a room heater
20. 20.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 88. What happens? (a) green LED ON (b) red LED ON
21. 21.🔋 2 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
22. 22.🧮 A 330 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
23. 23.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
24. 24.🔺 A 0.2 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
25. 25.Which of these is an insulator? (a) a copper wire (b) a metal paper clip (c) a brass key (d) a woollen thread
26. 26.🧩 Which component stores a little charge? (a) capacitor (b) LED (c) LDR (d) fuse
27. 27.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
28. 28.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) straight lines (c) wavy lines (d) little stars
29. 29.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) No (b) Yes
30. 30.🧩 Which component boosts a small signal? (a) motor (b) transistor (c) LED (d) buzzer
31. 31.True or false: a laptop runs one small program. (a) False (b) True
32. 32.True or false: to use small battery cells is safe. (a) True (b) False
33. 33.Which job needs a gas sensor? (a) spot someone walking in (b) warn of a gas leak (c) water a dry plant (d) switch on lamps at dusk
34. 34.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
35. 35.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
36. 36.⚡ A 36 W device works on 24 V. What current does it take (in amperes)? =
37. 37.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it changes colour (c) it makes a sound (d) it does not light
38. 38.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
39. 39.💡 What does LED stand for? (a) light-emitting diode (b) large electric dial (c) low energy device (d) light energy dial
40. 40.🌐 In an IoT system, which part shows data to you? (a) microcontroller (b) sensor (c) phone app (d) Wi-Fi

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