Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 476 · 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.⚠️ Why must we never touch switches with wet hands? (a) water makes it cold (b) it is just untidy (c) water carries current (d) it spoils the paint
2. 2.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 kilowatt-hour (kWh) (c) 1 watt (d) 1 ampere
3. 3.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) process (b) input (c) output
4. 4.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) False (b) True
5. 5.Which of these is not safe? (a) keep drinks far away (b) stay away from pylons (c) dry your hands first (d) touch a fallen wire
6. 6.🤖 if (sound > 60) { red LED ON } else { green LED ON }
   The sound sensor reads 43. What happens? (a) green LED ON (b) red LED ON
7. 7.True or false: to stay away from pylons is not safe. (a) True (b) False
8. 8.📏 Which unit measures power? (a) watt (W) (b) ohm (Ω) (c) volt (V) (d) ampere (A)
9. 9.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 5 V supply. What current flows (in mA)?
10. 10.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) always zero (c) more than either one (d) their sum
11. 11.True or false: “a button press” is the output. (a) True (b) False
12. 12.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) a wire is cut (d) the loop is complete
13. 13.🔁 repeat 6 times { repeat 2 times { beep } }
    How many beeps are there?
14. 14.🗺️ Before building a project, what should you write down first? (a) the box colour (b) inputs and outputs (c) the final price (d) nothing at all
15. 15.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
16. 16.🧮 Four equal 400 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
17. 17.🔺 A current of 20 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
18. 18.🔌 Is a servo motor an input or an output for a microcontroller? (a) output (b) input
19. 19.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) when both are OFF (c) when both are ON (d) never
20. 20.Which of these is a conductor? (a) a graphite rod (b) a rubber eraser (c) a plastic ruler (d) a glass marble
21. 21.🧩 Which component boosts a small signal? (a) resistor (b) motor (c) diode (d) transistor
22. 22.True or false: to stop a robot near walls, use a distance sensor. (a) False (b) True
23. 23.🔋 3 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
24. 24.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 1 cm. What happens? (a) buzzer beeps (b) buzzer is silent
25. 25.🔍 Which is the odd one out? (a) a rubber band (b) a copper wire (c) an iron nail (d) a graphite rod
26. 26.Which drawing is the symbol for a wire? (a) a plain rectangle (b) a straight line (c) a circle with an X in it (d) triangle against a bar
27. 27.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) only A is true (c) both are false (d) only B is true
28. 28.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
29. 29.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 3.5 V supply. What current flows (in mA)?
30. 30.Which of these gives us electricity? (a) a washing machine (b) an air conditioner (c) a generator (d) a water pump
31. 31.True or false: a diode stores a little charge. (a) True (b) False
32. 32.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
33. 33.🗺️ In an input → process → output plan, is “the pump turns on” the input, the process or the output? (a) output (b) process (c) input
34. 34.⚡ What does a water heater mainly change electricity into? (a) movement (b) sound (c) heat (d) light
35. 35.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) in parallel (d) by Wi-Fi
36. 36.🔍 Which is the odd one out? (a) a room heater (b) a rice cooker (c) an electric iron (d) a doorbell
37. 37.⏱️ loop forever { LED ON; wait 750 ms; LED OFF; wait 300 ms }
    How many milliseconds does one blink (ON + OFF) take?
38. 38.Which of these is not an IoT device? (a) a Wi-Fi smart plug (b) a pencil sharpener (c) a Wi-Fi weather station (d) a Wi-Fi doorbell camera
39. 39.Which of these is an insulator? (a) a brass key (b) an iron nail (c) a steel coin (d) a plastic straw
40. 40.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) voltmeter (b) bulb (c) battery (d) switch

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