Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 878 · 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 current of 0.1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
2. 2.Which of these is the input? (a) the pump turns on (b) a button press (c) an alert on the phone (d) an LED lights up
3. 3.🔺 A current of 1.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 2 hours?
5. 5.True or false: the flow of charge is measured in ohms (Ω). (a) True (b) False
6. 6.🔘 A bulb and a cell are joined through 2 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
7. 7.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
8. 8.True or false: a circle with M inside is the symbol for a motor. (a) False (b) True
9. 9.🔁 total = 0
   for i = 1 to 7 { total = total + i }
   What is total at the end?
10. 10.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
11. 11.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 290 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
12. 12.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
13. 13.Which job needs a distance sensor? (a) stop a robot near walls (b) warn of a gas leak (c) open blinds at sunrise (d) measure classroom noise
14. 14.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) each gets full voltage (d) so all go off together
15. 15.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
16. 16.⏱️ repeat 7 times { buzzer ON; wait 800 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
17. 17.True or false: a digital thermometer has no microcontroller inside. (a) True (b) False
18. 18.🌈 A resistor has the colour bands brown, grey, orange. What is its value in kilo-ohms (kΩ)? =
19. 19.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) an input (c) a fuse (d) a power source
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.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
22. 22.⚡ A device works on 3 V and takes 0.2 A. What is its power (in watts)? =
23. 23.🔌 Is a buzzer an input or an output for a microcontroller? (a) input (b) output
24. 24.🔺 A 12.5 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
25. 25.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) smaller (c) stay the same (d) zero
26. 26.💡 A battery lights 3 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
27. 27.Which of these is a good habit? (a) keep factory passwords (b) change default passwords (c) tap unknown app links (d) accept every permission
28. 28.Which of these has no microcontroller inside? (a) a microwave oven (b) a smart watch (c) a wind-up toy (d) a washing machine
29. 29.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = I ÷ V (d) P = V + I
30. 30.What does the phone app do? (a) measures the real world (b) carries the data (c) reads values, decides (d) shows data to you
31. 31.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
32. 32.True or false: “used in house wiring” is true of a series circuit. (a) False (b) True
33. 33.🔐 Privacy for a smart device means controlling … (a) its colour (b) how loud it beeps (c) its battery size (d) who can see your data
34. 34.⚡ A 12 W device works on 6 V. What current does it take (in amperes)? =
35. 35.💡 3 identical bulbs are joined in series with a 9 V battery (ideal wires). How many volts does each bulb get? =
36. 36.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 39 Ω resistor? (a) orange-white-black (b) white-orange-black (c) orange-white-brown (d) yellow-white-black
37. 37.🔌 Is a water pump an input or an output for a microcontroller? (a) output (b) input
38. 38.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
39. 39.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
40. 40.🔋 Identical cells side by side (in parallel) give … (a) the same voltage (b) double the voltage (c) no voltage (d) half the voltage

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