Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 578 · 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.🔋 3 identical 3 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
2. 2.True or false: “the fan starts” is the input. (a) False (b) True
3. 3.🌐 Is a battery torch an IoT device? (a) an IoT device (b) not an IoT device
4. 4.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) adds 1 to count (c) takes 1 away (d) prints 1
5. 5.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
6. 6.🔘 When a switch is ON, the circuit is … (a) cut (b) open (c) closed (d) broken
7. 7.🔢 To plan an electronics project, which is the LAST step? (a) pick a problem to solve (b) build it with an adult (c) draw the circuit diagram (d) test it and fix it
8. 8.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a plastic gap (d) a complete loop
9. 9.📏 Voltmeter or ammeter: which one measures current? (a) ammeter (b) voltmeter
10. 10.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
11. 11.True or false: a fuse smooths a wobbly supply. (a) True (b) False
12. 12.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
13. 13.What does a capacitor do? (a) is a resistance knob (b) senses how hot it is (c) makes a beeping sound (d) smooths a wobbly supply
14. 14.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
15. 15.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 2 glow? (a) Yes (b) No
16. 16.True or false: “each gets the full volts” is true of a parallel circuit. (a) True (b) False
17. 17.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the shorter line (c) the longer line (d) neither line
18. 18.Which of these is true of a series circuit? (a) each gets the full volts (b) used in house wiring (c) bulbs share the voltage (d) one out, the rest glow
19. 19.Which of these mainly makes sound? (a) a water heater (b) a loudspeaker (c) a mixer grinder (d) a table fan
20. 20.What does an LED do? (a) glows using little power (b) limits the current (c) boosts a small signal (d) has coloured bands
21. 21.Which of these means the circuit is open? (a) all wires are joined (b) the switch is OFF (c) the loop is complete (d) the switch is ON
22. 22.What does a potentiometer do? (a) senses how hot it is (b) senses how bright it is (c) limits the current (d) is a resistance knob
23. 23.Which of these is an output? (a) a motion sensor (b) a temperature sensor (c) a sound sensor (d) a servo motor
24. 24.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) by Wi-Fi (c) in parallel (d) not joined
25. 25.Which of these means the circuit is open? (a) a wire is cut (b) the switch is ON (c) the loop is complete (d) all wires are joined
26. 26.🔺 A current of 3 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
27. 27.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an input (c) a fuse (d) an output
28. 28.True or false: “a temperature reading” is the process. (a) False (b) True
29. 29.True or false: a capacitor smooths a wobbly supply. (a) False (b) True
30. 30.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = V + I (d) P = I ÷ V
31. 31.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 50 % (d) 5 %
32. 32.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a diode (c) a resistor (d) a capacitor
33. 33.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = V × R (d) I = R ÷ V
34. 34.True or false: to change default passwords is a good habit. (a) False (b) True
35. 35.True or false: a toggle switch flips up or down. (a) True (b) False
36. 36.⚠️ Why must we never touch switches with wet hands? (a) it is just untidy (b) it spoils the paint (c) water carries current (d) water makes it cold
37. 37.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) little stars (c) straight lines (d) dotted circles
38. 38.📏 How many watts (W) is 4.6 kW?
39. 39.🔍 Which is the odd one out? (a) a servo motor (b) a temperature sensor (c) a sound sensor (d) a motion sensor
40. 40.🤖 Does a smart watch usually have a microcontroller inside? (a) Yes (b) No

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