Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 785 · 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.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
2. 2.💡 What does LED stand for? (a) low energy device (b) large electric dial (c) light-emitting diode (d) light energy dial
3. 3.💡 4 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
4. 4.🔍 Which is the odd one out? (a) stay away from pylons (b) keep drinks far away (c) take cells out after use (d) open a phone charger
5. 5.True or false: a laptop runs many apps at once. (a) True (b) False
6. 6.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
7. 7.True or false: the voltmeter is joined in series. (a) False (b) True
8. 8.True or false: a siren mainly gives out light. (a) False (b) True
9. 9.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 160 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
10. 10.🔍 Which is the odd one out? (a) a plain wall switch (b) a pencil sharpener (c) a battery torch (d) an app-controlled bulb
11. 11.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a ceramic cup across the gap. Does the bulb glow? (a) No (b) Yes
12. 12.🔦 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) Yes (b) No
13. 13.True or false: a tilt switch closes when tipped over. (a) False (b) True
14. 14.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets bigger (c) gets smaller (d) becomes zero
15. 15.📏 How many amperes (A) is 1380 mA? =
16. 16.Which of these uses electricity? (a) a wind turbine (b) a bicycle dynamo (c) a solar panel (d) an air conditioner
17. 17.🧮 A 20 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
18. 18.True or false: a tilt switch stays where you flip it. (a) True (b) False
19. 19.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.True or false: an LED stores a little charge. (a) False (b) True
21. 21.🔺 A current of 0.25 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
22. 22.🧩 A capacitor in a circuit can … (a) store charge briefly (b) measure heat (c) spin a wheel (d) make light
23. 23.📶 How many states can a digital pin have? (a) one (b) two (c) ten (d) a thousand
24. 24.✏️ In a circuit diagram, which part is drawn as a straight line? (a) bulb (b) capacitor (c) wire (d) voltmeter
25. 25.True or false: a microcontroller runs one small program. (a) False (b) True
26. 26.🔋 How many 3 V cells must be joined in series to give 24 V?
27. 27.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to limit the current (c) to change its colour (d) to store charge
28. 28.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) it is sent by Wi-Fi (b) the app shows it (c) the board reads it (d) the sensor measures
29. 29.Which of these mainly gives out light? (a) a torch (b) a loudspeaker (c) a buzzer (d) a room heater
30. 30.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 200 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
31. 31.🌈 A resistor has the colour bands grey, grey, yellow. What is its value in kilo-ohms (kΩ)? =
32. 32.🔁 x = 3
    repeat 5 times { x = x × 2 }
    What is x at the end?
33. 33.True or false: to start a fan when hot, use a soil moisture sensor. (a) True (b) False
34. 34.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
35. 35.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
36. 36.Which of these is measured in watts (W)? (a) voltage (b) the push of a cell (c) resistance (d) energy used each second
37. 37.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) little stars (c) wavy lines (d) straight lines
38. 38.🔐 Is it a good or a risky habit to tap unknown app links? (a) risky habit (b) good habit
39. 39.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
40. 40.💡 A red LED uses 2 V and should get 25 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?

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