Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 357 · 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 sensor would you use to make a parking alarm? (a) a soil moisture sensor (b) a distance sensor (c) a sound sensor (d) a gas sensor
2. 2.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
3. 3.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the colour of light (d) the length of a wire
4. 4.📶 A pin that reads a push button is set as … (a) a resistor (b) a battery (c) an output (d) an input
5. 5.🔐 Is it a good or a risky habit to ignore update messages? (a) good habit (b) risky habit
6. 6.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
7. 7.🔦 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) No (b) Yes
8. 8.Which of these is not an IoT device? (a) a wind-up clock (b) a fitness band with app (c) an app-controlled bulb (d) a Wi-Fi weather station
9. 9.True or false: a steel coin is a conductor. (a) True (b) False
10. 10.🧮 A 3.2 V battery is joined to 4 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
11. 11.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V + I (c) R = V × I (d) R = V ÷ I
12. 12.True or false: “a single current path” is true of a series circuit. (a) False (b) True
13. 13.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) switch (b) cell (c) wire (d) bulb
14. 14.🔘 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 ON. Does the bulb glow? (a) Yes (b) No
15. 15.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 10 (c) 60 (d) 100
16. 16.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 18 °C. What is shown? (a) Cool (b) Hot (c) Warm
17. 17.Which of these is safe? (a) use a cable with cuts (b) throw cells in a fire (c) use mains for a project (d) use small battery cells
18. 18.🔦 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
19. 19.🔁 What does a variable do in a program? (a) joins two wires (b) blinks an LED (c) stores a value (d) measures light
20. 20.True or false: “own switch for each bulb” is true of a parallel circuit. (a) False (b) True
21. 21.Which of these is not an IoT device? (a) an app-controlled bulb (b) a Wi-Fi weather station (c) a smart energy meter (d) a battery torch
22. 22.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
23. 23.🔍 Which is the odd one out? (a) a cotton thread (b) a woollen thread (c) a dry cork (d) aluminium foil
24. 24.💡 A battery lights 3 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
25. 25.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) an output (c) an input (d) a power source
26. 26.Which of these wastes electricity? (a) switch off empty rooms (b) leave fridge door open (c) use daylight to read (d) set the AC to 24 °C
27. 27.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = I ÷ R (c) V = I × R (d) V = R ÷ I
28. 28.🔗 Series or parallel circuit: “a break stops every bulb”? (a) parallel (b) series
29. 29.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) ammeter (b) LED (c) voltmeter (d) cell
30. 30.Which job is done by the USB port? (a) connect sensors and LEDs (b) brings power and code (c) restarts the program (d) shows the board is on
31. 31.🔘 A bulb and a cell are joined through 2 switches on 2 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?
32. 32.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
33. 33.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) False (b) True
34. 34.🔺 A current of 40 mA flows when 16 V is joined across a resistor. What is its resistance (in ohms)?
35. 35.True or false: “used in house wiring” is true of a series circuit. (a) True (b) False
36. 36.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 67. What happens? (a) green LED ON (b) red LED ON
37. 37.🔺 A current of 25 mA flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?
38. 38.🔺 A current of 1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
39. 39.💡 3 identical bulbs are joined in series with a 4.5 V battery (ideal wires). How many volts does each bulb get? =
40. 40.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) battery (b) wire (c) capacitor (d) resistor

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