Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 920 · 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.🧾 A 2000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
2. 2.Which job needs a gas sensor? (a) open blinds at sunrise (b) start a fan when hot (c) switch on with a clap (d) warn of a gas leak
3. 3.Which of these is a risky habit? (a) set a strong password (b) share camera links (c) change default passwords (d) turn off unused gadgets
4. 4.🔢 To plan an electronics project, which is the FIRST step? (a) list inputs and outputs (b) test it and fix it (c) pick a problem to solve (d) build it with an adult
5. 5.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
6. 6.True or false: to switch on lamps at dusk, use a light sensor. (a) False (b) True
7. 7.True or false: “each gets the full volts” is true of a series circuit. (a) False (b) True
8. 8.True or false: the ammeter is joined across a part. (a) True (b) False
9. 9.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
10. 10.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
11. 11.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
12. 12.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) switch (b) wire (c) cell (d) ammeter
13. 13.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a series circuit (d) a closed circuit
14. 14.What does a toggle switch do? (a) works only while pressed (b) flips up or down (c) slides side to side (d) springs back when let go
15. 15.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) diode (b) junction (c) switch (d) motor
16. 16.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
17. 17.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) stay the same (d) bigger
18. 18.⚡ A 0.6 W device works on 3 V. What current does it take (in amperes)? =
19. 19.🔺 A current of 25 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
20. 20.🌐 In an IoT system, which part reads values, decides? (a) microcontroller (b) phone app (c) Wi-Fi (d) sensor
21. 21.💡 What does LED stand for? (a) light-emitting diode (b) light energy dial (c) low energy device (d) large electric dial
22. 22.Which drawing is the symbol for a diode? (a) triangle against a bar (b) a circle with a cross (c) a small empty box (d) a circle with V inside
23. 23.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) in series (d) not joined
24. 24.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a short circuit (b) an open circuit (c) a parallel circuit (d) a safe circuit
25. 25.🧩 Which component glows using little power? (a) resistor (b) LED (c) thermistor (d) capacitor
26. 26.🔁 x = 2
    repeat 5 times { x = x × 2 }
    What is x at the end?
27. 27.True or false: a tilt switch closes when tipped over. (a) True (b) False
28. 28.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 37 %. What happens? (a) pump OFF (b) pump ON
29. 29.📶 Digital or analog: a door: open or shut? (a) analog (b) digital
30. 30.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) neither part (d) the if part
31. 31.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
32. 32.True or false: a night lamp mainly gives out light. (a) False (b) True
33. 33.🔺 A current of 0.25 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
34. 34.🔍 Which is the odd one out? (a) a ceiling fan (b) a table fan (c) a toaster (d) a mixer grinder
35. 35.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is OFF, B is OFF, C is OFF and D is OFF. Does the bulb glow? (a) No (b) Yes
36. 36.Which of these means the circuit is open? (a) the loop is complete (b) the switch is OFF (c) the switch is ON (d) all wires are joined
37. 37.🔌 Why are electric wires covered in plastic? (a) plastic makes current (b) plastic is a conductor (c) plastic is an insulator (d) to make them heavy
38. 38.🔁 count = 0
    repeat 3 times { count = count + 10 }
    What is count at the end?
39. 39.Which of these is not an IoT device? (a) a Wi-Fi smart plug (b) an app-controlled bulb (c) a wind-up clock (d) a Wi-Fi weather station
40. 40.🔁 count = 4
    repeat 4 times { count = count + 2 }
    What is count at the end?

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