Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 122 · 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.🔘 What does a switch do in a circuit? (a) makes electricity (b) stores current (c) changes the voltage (d) opens or closes the loop
2. 2.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) turns the LED off (c) blinks 500 times (d) pauses for half a second
3. 3.🤖 What is a microcontroller? (a) a computer on one chip (b) a type of battery (c) a kind of bulb (d) a big desktop computer
4. 4.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) a motor (d) an LED
5. 5.🔺 A 4 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
6. 6.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave fridge door open (c) leave the TV on standby (d) use LED lamps
7. 7.True or false: the voltmeter measures voltage. (a) True (b) False
8. 8.🧮 Resistors of 330 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
9. 9.True or false: a laptop uses very little power. (a) True (b) False
10. 10.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
11. 11.🔗 Series or parallel circuit: “own switch for each bulb”? (a) series (b) parallel
12. 12.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a ceramic cup across the gap. Does the bulb glow? (a) Yes (b) No
13. 13.🔋 A 12 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
14. 14.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
15. 15.Which of these is true of a parallel circuit? (a) a single current path (b) bulbs share the voltage (c) one bulb out, all go out (d) each gets the full volts
16. 16.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
17. 17.🗺️ Before building a project, what should you write down first? (a) nothing at all (b) the box colour (c) the final price (d) inputs and outputs
18. 18.🌈 A resistor has the colour bands green, grey, brown. What is its value (in ohms)?
19. 19.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) gets smaller (c) stays the same (d) becomes zero
20. 20.🔗 Series or parallel circuit: “each gets the full volts”? (a) parallel (b) series
21. 21.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
22. 22.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
23. 23.True or false: a buzzer makes a beeping sound. (a) True (b) False
24. 24.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 6 hours?
25. 25.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
26. 26.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 2 glow? (a) Yes (b) No
27. 27.Which of these mainly makes sound? (a) a toaster (b) a mixer grinder (c) a traffic signal (d) a siren
28. 28.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
29. 29.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 650 ms }
    How many times does the LED blink in 5 seconds?
30. 30.🔘 Which kind of switch slides side to side? (a) a push button (b) a tilt switch (c) a toggle switch (d) a slide switch
31. 31.Which of these is true of a series circuit? (a) own switch for each bulb (b) many paths for current (c) used in house wiring (d) bulbs share the voltage
32. 32.Which of these is measured in volts (V)? (a) the flow of charge (b) how much a part resists (c) the push of a cell (d) resistance
33. 33.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
34. 34.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
35. 35.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a safety pin across the gap. Does the bulb glow? (a) No (b) Yes
36. 36.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 230 V (c) 0.5 V (d) 1.5 V
37. 37.True or false: a resistor has coloured bands. (a) True (b) False
38. 38.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
39. 39.🔐 Why install updates on IoT devices? (a) they fix security holes (b) they change the colour (c) they delete the Wi-Fi (d) they make it heavier
40. 40.What does a capacitor do? (a) senses how hot it is (b) makes a beeping sound (c) smooths a wobbly supply (d) beeps for an alarm

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