Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 954 · 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.Which of these has no microcontroller inside? (a) a toy robot (b) a digital alarm clock (c) a microwave oven (d) a hand pump
2. 2.True or false: a smart watch has no microcontroller inside. (a) False (b) True
3. 3.🔺 A 12.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
4. 4.🔍 Which is the odd one out? (a) a torch (b) a rice cooker (c) a street light (d) a night lamp
5. 5.💡 2 identical bulbs are joined in series with a 2 V battery (ideal wires). How many volts does each bulb get? =
6. 6.What does a buzzer do? (a) glows using little power (b) lets current go one way (c) smooths a wobbly supply (d) makes a beeping sound
7. 7.📏 How many ohms (Ω) is 2.7 kΩ?
8. 8.🔺 A current of 2 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.💡 3 identical bulbs are joined in series with a 9 V battery (ideal wires). How many volts does each bulb get? =
10. 10.True or false: a circle with M inside is the symbol for a junction. (a) False (b) True
11. 11.🔺 A current of 25 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
12. 12.Which of these is a good habit? (a) post your live location (b) ignore update messages (c) install software updates (d) keep factory passwords
13. 13.🔍 Which is the odd one out? (a) a button press (b) a temperature reading (c) a soil moisture reading (d) count button presses
14. 14.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
15. 15.🔁 What does a variable do in a program? (a) measures light (b) joins two wires (c) stores a value (d) blinks an LED
16. 16.Which of these is a conductor? (a) a ceramic cup (b) aluminium foil (c) a paper strip (d) a glass marble
17. 17.🔁 count = 1
    repeat 9 times { count = count + 4 }
    What is count at the end?
18. 18.🤖 if (temperature > 28) { fan ON } else { fan OFF }
    The temperature sensor reads 31 °C. What happens? (a) fan OFF (b) fan ON
19. 19.🔋 Identical cells side by side (in parallel) give … (a) no voltage (b) double the voltage (c) half the voltage (d) the same voltage
20. 20.⏱️ repeat 4 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
21. 21.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 440 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
22. 22.True or false: aluminium foil is a conductor. (a) False (b) True
23. 23.🧩 Which component smooths a wobbly supply? (a) fuse (b) buzzer (c) resistor (d) capacitor
24. 24.True or false: “each gets the full volts” is true of a parallel circuit. (a) True (b) False
25. 25.💡 3 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
26. 26.Which of these is an insulator? (a) a brass key (b) a copper wire (c) a safety pin (d) a plastic straw
27. 27.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
28. 28.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
29. 29.Which job needs a distance sensor? (a) switch on with a clap (b) keep an incubator warm (c) open blinds at sunrise (d) make a parking alarm
30. 30.📏 How many amperes (A) is 1110 mA? =
31. 31.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
32. 32.Which job needs a motor? (a) spin a robot’s wheels (b) show a status light (c) show the temperature (d) beep an alarm
33. 33.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
34. 34.True or false: to use daylight to read wastes electricity. (a) True (b) False
35. 35.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the battery (b) the process (c) the input (d) the output
36. 36.⏱️ How many milliseconds is a wait of 2.4 seconds?
37. 37.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 9400 Ω resistor? (a) white-yellow-orange (b) white-yellow-red (c) yellow-white-red (d) white-yellow-brown
38. 38.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
39. 39.Which of these is an insulator? (a) a cotton thread (b) a brass key (c) a copper wire (d) a graphite rod
40. 40.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a cotton thread across the gap. Does the bulb glow? (a) Yes (b) No

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