Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 204 · 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.True or false: a push button flips up or down. (a) False (b) True
2. 2.💡 4 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?
3. 3.Which of these is measured in amperes (A)? (a) power (b) resistance (c) the flow of charge (d) energy used each second
4. 4.🔺 A current of 20 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
5. 5.⏱️ loop forever { LED ON; wait 600 ms; LED OFF; wait 250 ms }
   How many milliseconds does one blink (ON + OFF) take?
6. 6.🔍 Which is the odd one out? (a) post your live location (b) tap unknown app links (c) share camera links (d) log out of shared phones
7. 7.🔺 A current of 10 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
8. 8.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
9. 9.🔋 How many 1.2 V cells must be joined in series to give 2.4 V?
10. 10.🔋 What is a battery? (a) two or more cells joined (b) a kind of bulb (c) one single wire (d) a switch with a lid
11. 11.Which of these is the output? (a) a soil moisture reading (b) decide if soil is dry (c) compare with a limit (d) the pump turns on
12. 12.True or false: “how bright a room is” is an analog signal. (a) True (b) False
13. 13.True or false: aluminium foil is a conductor. (a) False (b) True
14. 14.✏️ In a circuit diagram, which part is drawn as a circle with a cross? (a) capacitor (b) switch (c) motor (d) bulb
15. 15.Which of these has no microcontroller inside? (a) a digital alarm clock (b) a washing machine (c) a TV remote (d) a wind-up toy
16. 16.True or false: a circle with M inside is the symbol for a motor. (a) False (b) True
17. 17.🔁 repeat 6 times { repeat 6 times { beep } }
    How many beeps are there?
18. 18.True or false: a metal paper clip is an insulator. (a) True (b) False
19. 19.🔺 A 10 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
20. 20.True or false: to set the AC to 24 °C wastes electricity. (a) False (b) True
21. 21.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
22. 22.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
23. 23.What does the Wi-Fi link do? (a) reads values, decides (b) acts on a command (c) measures the real world (d) carries the data
24. 24.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) stay the same (c) zero (d) smaller
25. 25.🌈 In the resistor colour code, which number does white stand for?
26. 26.⚠️ Is it safe to take cells out after use? (a) safe (b) not safe
27. 27.Which of these is an insulator? (a) an iron nail (b) a safety pin (c) a ceramic cup (d) a copper wire
28. 28.True or false: the voltmeter is joined across a part. (a) False (b) True
29. 29.⚡ A 7.5 W device works on 5 V. What current does it take (in amperes)? =
30. 30.💡 3 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. Bulb 2 is taken out of its holder. How many bulbs glow?
31. 31.🔍 An object is 119 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
32. 32.True or false: “a tilt switch: on or off” is an analog signal. (a) True (b) False
33. 33.🌈 A resistor has the colour bands yellow, yellow, orange. What is its value in kilo-ohms (kΩ)? =
34. 34.💡 What does LED stand for? (a) light-emitting diode (b) light energy dial (c) low energy device (d) large electric dial
35. 35.What does the actuator do? (a) acts on a command (b) measures the real world (c) stores data online (d) carries the data
36. 36.🤖 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
37. 37.🌈 A resistor has the colour bands white, brown, yellow. What is its value in kilo-ohms (kΩ)? =
38. 38.💡 Why does an LED need a resistor in series? (a) to change its colour (b) to limit the current (c) to store charge (d) to make it brighter
39. 39.🌈 A resistor has the colour bands blue, brown, black. What is its value (in ohms)?
40. 40.⚠️ Why must we never touch switches with wet hands? (a) it is just untidy (b) it spoils the paint (c) water makes it cold (d) water carries current

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