Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 518 · 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 12 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
2. 2.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are OFF (b) never (c) when either is ON (d) only when both are ON
3. 3.💡 6 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 2 and 3 are taken out of their holders. Does bulb 6 glow? (a) Yes (b) No
4. 4.🔐 Privacy for a smart device means controlling … (a) its colour (b) its battery size (c) who can see your data (d) how loud it beeps
5. 5.True or false: “a single current path” is true of a series circuit. (a) True (b) False
6. 6.⚡ A device works on 3 V and takes 2 A. What is its power (in watts)? =
7. 7.🔁 count = 5
   while (count < 30) { count = count + 5 }
   How many times does the loop run?
8. 8.⚡ A device works on 9 V and takes 0.1 A. What is its power (in watts)? =
9. 9.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V ÷ R (c) I = V + R (d) I = V × R
10. 10.What does a motor do? (a) lets current go one way (b) is a resistance knob (c) beeps for an alarm (d) makes things spin
11. 11.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 volt (d) 1 ampere
12. 12.🔍 Which is the odd one out? (a) a motion sensor signal (b) a temperature reading (c) an alert on the phone (d) a soil moisture reading
13. 13.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) store charge briefly (d) make light
14. 14.🗺️ In an input → process → output plan, is “check if temp > 30” the input, the process or the output? (a) input (b) output (c) process
15. 15.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
16. 16.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) less than either one (c) their sum (d) always zero
17. 17.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 350 ms }
    How many milliseconds does one blink (ON + OFF) take?
18. 18.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
19. 19.🌐 What does IoT stand for? (a) Internet of Talk (b) Inside of Toys (c) Internet of Things (d) Input of Tools
20. 20.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) No (b) Yes
21. 21.🔺 A 2.4 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
22. 22.🔌 Is a cotton thread a conductor or an insulator? (a) a conductor (b) an insulator
23. 23.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the if part (c) the else part (d) neither part
24. 24.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 22 °C. What is shown? (a) Cool (b) Hot (c) Warm
25. 25.Which of these is safe? (a) stay away from pylons (b) poke things in a socket (c) open a phone charger (d) climb an electric pole
26. 26.⚠️ Is it safe to poke things in a socket? (a) not safe (b) safe
27. 27.Which of these usually has a microcontroller inside? (a) a spinning top (b) a wind-up toy (c) a candle (d) a microwave oven
28. 28.🔌 Is a ceramic cup a conductor or an insulator? (a) a conductor (b) an insulator
29. 29.Which of these is true of a series circuit? (a) used in house wiring (b) one bulb out, all go out (c) own switch for each bulb (d) each gets the full volts
30. 30.🔋 What should you do with used-up cells? (a) cut them open (b) throw them in a fire (c) bury them in soil (d) give them for recycling
31. 31.🔘 Which kind of switch closes near a magnet? (a) a tilt switch (b) a reed switch (c) a slide switch (d) a toggle switch
32. 32.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
33. 33.🧮 A 10 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
34. 34.🔍 Which sensor would you use to spot someone walking in? (a) a motion sensor (b) a soil moisture sensor (c) a sound sensor (d) a rain sensor
35. 35.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
36. 36.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
37. 37.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
38. 38.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) blinks an LED (d) stores a value
39. 39.🔘 When a switch is ON, the circuit is … (a) broken (b) open (c) cut (d) closed
40. 40.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON

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