Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 110 · 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.🔁 repeat 6 times { repeat 4 times { beep } }
   How many beeps are there?
2. 2.🔍 Which is the odd one out? (a) a battery torch (b) a Wi-Fi smart plug (c) a wind-up clock (d) a plain wall switch
3. 3.True or false: to build with an adult near is safe. (a) False (b) True
4. 4.🌈 In the resistor colour code, which number does blue stand for?
5. 5.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) capacitor (b) bulb (c) junction (d) diode
6. 6.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. How many bulbs glow?
7. 7.Which of these is an insulator? (a) aluminium foil (b) a steel spoon (c) a woollen thread (d) a safety pin
8. 8.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
9. 9.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
10. 10.🤖 “if (A AND B)” is true when … (a) only A is true (b) both are false (c) only B is true (d) both A and B are true
11. 11.🔁 count = 9
    repeat 10 times { count = count + 3 }
    What is count at the end?
12. 12.⚡ A fan changes electrical energy mainly into which kind of energy? (a) light energy (b) chemical energy (c) sound energy (d) movement energy
13. 13.🔦 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
14. 14.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
15. 15.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
16. 16.🧮 Resistors of 100 Ω, 68 Ω, 220 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
17. 17.True or false: a reed switch closes near a magnet. (a) True (b) False
18. 18.🔍 An object is 68 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
19. 19.📶 Digital or analog: many values in a range? (a) digital (b) analog
20. 20.⏱️ How many milliseconds is a wait of 1.2 seconds?
21. 21.What does a tilt switch do? (a) flips up or down (b) springs back when let go (c) closes when tipped over (d) closes near a magnet
22. 22.💡 Why is house wiring done in parallel? (a) to save copper only (b) each gets full voltage (c) so all go off together (d) to make bulbs dim
23. 23.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
24. 24.🔋 3 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
25. 25.⚠️ Is it safe to use a cable with cuts? (a) safe (b) not safe
26. 26.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 43 Ω resistor? (a) yellow-orange-brown (b) green-orange-black (c) orange-yellow-black (d) yellow-orange-black
27. 27.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
28. 28.🌈 A resistor has the colour bands green, black, black. What is its value (in ohms)?
29. 29.True or false: two or more cell symbols is the symbol for a battery. (a) True (b) False
30. 30.🔍 Which is the odd one out? (a) fly kites in open fields (b) open a phone charger (c) stay away from pylons (d) dry your hands first
31. 31.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
32. 32.🔁 repeat 3 times { repeat 6 times { beep } }
    How many beeps are there?
33. 33.🔺 A current of 0.25 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
34. 34.💡 A battery lights 2 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
35. 35.Which job needs a temperature sensor? (a) open blinds at sunrise (b) start a fan when hot (c) switch on with a clap (d) water a dry plant
36. 36.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
37. 37.🧮 A 220 Ω resistor is joined in series with two equal 200 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
38. 38.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 450 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
39. 39.Which of these is a conductor? (a) a rubber band (b) a brass key (c) a plastic straw (d) a plastic ruler
40. 40.🔺 A current of 25 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =

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