Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 137 · 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.Which of these wastes electricity? (a) use daylight to read (b) leave the TV on standby (c) close the fridge quickly (d) use LED lamps
2. 2.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) a single current path (c) a break stops every bulb (d) one out, the rest glow
3. 3.🔺 A 50 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
4. 4.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
5. 5.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
   The temperature is 16 °C. What is shown? (a) Warm (b) Cool (c) Hot
6. 6.⚠️ Is it safe to touch a fallen wire? (a) not safe (b) safe
7. 7.Which of these is true of a series circuit? (a) each gets the full volts (b) one out, the rest glow (c) a break stops every bulb (d) many paths for current
8. 8.🔺 A 16 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
9. 9.📏 How many kilowatts (kW) is 1400 W? =
10. 10.⏱️ How many milliseconds is a wait of 0.2 seconds?
11. 11.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the colour of light (d) the size of a cell
12. 12.💡 2 identical bulbs are joined in series with a 4 V battery (ideal wires). How many volts does each bulb get? =
13. 13.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
14. 14.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 9 seconds?
15. 15.Which of these is measured in ohms (Ω)? (a) the flow of charge (b) the push of a cell (c) resistance (d) voltage
16. 16.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
17. 17.What does a toggle switch do? (a) closes near a magnet (b) slides side to side (c) springs back when let go (d) stays where you flip it
18. 18.🔍 Which is the odd one out? (a) share only needed data (b) accept every permission (c) tap unknown app links (d) ignore update messages
19. 19.🌐 In an IoT system, which part acts on a command? (a) actuator (b) cloud server (c) Wi-Fi (d) sensor
20. 20.📏 How many kilo-ohms (kΩ) is 10000 Ω? =
21. 21.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
22. 22.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
23. 23.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) battery (b) capacitor (c) motor (d) cell
24. 24.🔍 Which is the odd one out? (a) a safety pin (b) a metal paper clip (c) a glass marble (d) a brass key
25. 25.Which of these is safe? (a) stay away from pylons (b) use mains for a project (c) fly a kite near wires (d) climb an electric pole
26. 26.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the main chip (b) the pins (c) the power LED (d) the USB port
27. 27.True or false: to use daylight to read saves electricity. (a) True (b) False
28. 28.True or false: the flow of charge is measured in watts (W). (a) True (b) False
29. 29.🧮 Four equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
30. 30.💡 In a series circuit, how many paths does the current have? (a) none (b) two (c) one (d) one for each bulb
31. 31.True or false: to throw cells in a fire is not safe. (a) False (b) True
32. 32.Which drawing is the symbol for a capacitor? (a) a circle with a cross (b) a small empty box (c) two equal parallel lines (d) a circle with A inside
33. 33.🔌 Why are electric wires covered in plastic? (a) to make them heavy (b) plastic is an insulator (c) plastic is a conductor (d) plastic makes current
34. 34.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) voltmeter (b) capacitor (c) battery (d) LED
35. 35.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 419. What happens? (a) lamp ON (b) lamp OFF
36. 36.Which drawing is the symbol for an ammeter? (a) a long and a short line (b) a circle with A inside (c) triangle, bar and arrows (d) many long-short pairs
37. 37.True or false: a tilt switch stays where you flip it. (a) False (b) True
38. 38.⚠️ Is it safe to poke things in a socket? (a) safe (b) not safe
39. 39.🔘 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?
40. 40.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No

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