Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 227 · 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 four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
2. 2.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a brass key across the gap. Does the bulb glow? (a) Yes (b) No
3. 3.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) output (b) input
4. 4.💡 6 identical bulbs are in parallel and each one takes 0.5 A. What total current (in amperes) comes from the battery? =
5. 5.Which of these wastes electricity? (a) use daylight to read (b) unplug idle chargers (c) iron one shirt at a time (d) switch off empty rooms
6. 6.Which of these is safe? (a) use a cable with cuts (b) fly a kite near wires (c) touch a switch when wet (d) stay away from pylons
7. 7.True or false: a circle with an X in it is the symbol for a bulb. (a) False (b) True
8. 8.⚡ What does a night lamp mainly change electricity into? (a) heat (b) sound (c) light (d) movement
9. 9.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) an input (c) an output (d) a power source
10. 10.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
11. 11.🔘 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?
12. 12.🔦 A circuit has a used-up (dead) 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 paper strip. Does the bulb glow? (a) Yes (b) No
13. 13.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) No (b) Yes
14. 14.True or false: to use small battery cells is safe. (a) True (b) False
15. 15.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 9 minutes?
16. 16.True or false: the voltmeter is joined in series. (a) True (b) False
17. 17.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 10 (c) 60 (d) 1000
18. 18.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 400 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
19. 19.Which drawing is the symbol for a bulb? (a) a circle with V inside (b) a circle with an X in it (c) a straight line (d) triangle, bar and arrows
20. 20.🔌 Why are electric wires covered in plastic? (a) to make them heavy (b) plastic is a conductor (c) plastic makes current (d) plastic is an insulator
21. 21.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) always zero (c) their sum (d) more than either one
22. 22.Which of these is an output? (a) a light sensor (b) a keypad (c) a push button (d) a servo motor
23. 23.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 96 Ω resistor? (a) blue-white-black (b) white-blue-brown (c) white-blue-black (d) brown-blue-black
24. 24.True or false: the voltmeter measures current. (a) False (b) True
25. 25.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 5 minutes?
26. 26.🔋 7 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
27. 27.🔺 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
28. 28.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
29. 29.Which job needs a motion sensor? (a) spot someone walking in (b) warn of a gas leak (c) open blinds at sunrise (d) start a fan when hot
30. 30.Which of these is safe? (a) dry your hands first (b) throw cells in a fire (c) fly a kite near wires (d) open a phone charger
31. 31.🔍 Which is the odd one out? (a) a pencil sharpener (b) a plain table fan (c) a plain wall switch (d) an app-controlled bulb
32. 32.Which of these is true of a series circuit? (a) own switch for each bulb (b) each gets the full volts (c) one out, the rest glow (d) a single current path
33. 33.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) only B is true (c) both are false (d) only A is true
34. 34.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) the sensor measures (b) it is sent by Wi-Fi (c) the board reads it (d) the app shows it
35. 35.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 1000 ms }
    How many milliseconds does one blink (ON + OFF) take?
36. 36.🗺️ Before building a project, what should you write down first? (a) inputs and outputs (b) the final price (c) nothing at all (d) the box colour
37. 37.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V + I (c) P = V ÷ I (d) P = V × I
38. 38.What does the microcontroller do? (a) acts on a command (b) stores data online (c) shows data to you (d) reads values, decides
39. 39.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) stores a value (d) blinks an LED
40. 40.⏱️ repeat 7 times { buzzer ON; wait 500 ms; buzzer OFF; wait 900 ms }
    How many milliseconds does this take in all?

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