Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 209 · 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.True or false: a torch mainly makes movement. (a) False (b) True
2. 2.True or false: one tall, one short bar is the symbol for a cell. (a) False (b) True
3. 3.💡 An LED is joined to a 12 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) lights up (c) does not light
4. 4.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I × R (d) V = I ÷ R
5. 5.🔌 A gap of dry air between two wires acts as … (a) a cell (b) an insulator (c) a switch that is ON (d) a conductor
6. 6.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to make it colourful (c) quick and clear for all (d) to hide the circuit
7. 7.🔋 Does a generator give electricity or use electricity? (a) uses electricity (b) gives electricity
8. 8.🔺 A current of 0.1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
9. 9.True or false: a circle with A inside is the symbol for an ammeter. (a) False (b) True
10. 10.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
11. 11.⚡ What do we call a flow of electric charge through a wire? (a) electric current (b) a magnet (c) sound (d) friction
12. 12.💡 2 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. Does bulb 1 glow? (a) Yes (b) No
13. 13.🌐 What does IoT stand for? (a) Internet of Talk (b) Input of Tools (c) Inside of Toys (d) Internet of Things
14. 14.🔢 To plan an electronics project, what comes right after “pick a problem to solve”? (a) build it with an adult (b) test it and fix it (c) draw the circuit diagram (d) list inputs and outputs
15. 15.⚡ Power tells us … (a) energy used each second (b) the colour of light (c) the length of a wire (d) the size of a cell
16. 16.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the main chip (b) the reset button (c) the voltage regulator (d) the pins
17. 17.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) wire (b) voltmeter (c) motor (d) bulb
18. 18.🌈 In the resistor colour code, which number does brown stand for?
19. 19.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
20. 20.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a bulb (b) a fuse or MCB (c) a plug top (d) a long wire
21. 21.True or false: an LED glows using little power. (a) False (b) True
22. 22.🔍 Which is the odd one out? (a) a smart energy meter (b) a fitness band with app (c) a wind-up clock (d) a Wi-Fi smart plug
23. 23.🔺 A current of 50 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
24. 24.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
25. 25.🔌 Is an LED an input or an output for a microcontroller? (a) output (b) input
26. 26.⚙️ Which actuator would you use to move water to plants? (a) an LED (b) a buzzer (c) a servo motor (d) a pump
27. 27.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) wait a few seconds (b) switch the pump on/off (c) compare with the limit
28. 28.Which of these is a risky habit? (a) set a strong password (b) install software updates (c) share camera links (d) cover unused cameras
29. 29.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
30. 30.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
31. 31.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
32. 32.True or false: a resistor senses how hot it is. (a) True (b) False
33. 33.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) straight lines (c) little stars (d) dotted circles
34. 34.Which drawing is the symbol for a battery? (a) a small empty box (b) triangle against a bar (c) two or more cell symbols (d) a long and a short line
35. 35.⚙️ Which actuator would you use to show the temperature? (a) a display (b) a servo motor (c) a pump (d) a buzzer
36. 36.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
37. 37.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) neither line (c) the shorter line (d) the longer line
38. 38.True or false: a thermistor beeps for an alarm. (a) True (b) False
39. 39.Which of these mainly gives out heat? (a) a school bell (b) a room heater (c) a traffic signal (d) a siren
40. 40.Which of these has no microcontroller inside? (a) a microwave oven (b) a toy robot (c) a hand pump (d) a digital alarm clock

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