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Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 988 · 40 questions
TalentJR

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.

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  1. 1.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) bigger (c) smaller (d) zero
  2. 2.Which job needs a servo motor? (a) move water to plants (b) turn to an exact angle (c) beep an alarm (d) show the temperature
  3. 3.🔁 count = 1
    while (count < 25) { count = count + 4 }
    How many times does the loop run?
  4. 4.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 390 and motion is detected (true). What happens?     (a) porch lamp ON (b) porch lamp OFF
  5. 5.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
  6. 6.🔍 Which is the odd one out? (a) dry your hands first (b) poke things in a socket (c) keep drinks far away (d) fly kites in open fields
  7. 7.⚠️ Is it safe to touch a fallen wire? (a) safe (b) not safe
  8. 8.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = V + I (c) R = I ÷ V (d) R = V ÷ I
  9. 9.🔺 A current of 0.25 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
  10. 10.⚡ A solar panel changes which kind of energy into electricity? (a) wind energy (b) light energy (c) chemical energy (d) sound energy
  11. 11.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
  12. 12.🔐 Is it a good or a risky habit to keep factory passwords? (a) risky habit (b) good habit
  13. 13.True or false: a digital alarm clock usually has a microcontroller inside. (a) True (b) False
  14. 14.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
  15. 15.🔍 Which is the odd one out? (a) keep drinks far away (b) use small battery cells (c) dry your hands first (d) open a phone charger
  16. 16.Which of these is measured in amperes (A)? (a) energy used each second (b) resistance (c) how much a part resists (d) current
  17. 17.🔘 When a switch is ON, the circuit is … (a) open (b) broken (c) closed (d) cut
  18. 18.🔍 Which is the odd one out? (a) an LED lights up (b) an alert on the phone (c) count button presses (d) the fan starts
  19. 19.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = R ÷ V (c) I = V ÷ R (d) I = V × R
  20. 20.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
  21. 21.True or false: to use mains for a project is safe. (a) True (b) False
  22. 22.🔌 Is a steel spoon a conductor or an insulator? (a) a conductor (b) an insulator
  23. 23.⚡ A fan changes electrical energy mainly into which kind of energy? (a) chemical energy (b) light energy (c) sound energy (d) movement energy
  24. 24.True or false: the voltmeter measures current. (a) True (b) False
  25. 25.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) prints 1 (d) adds 1 to count
  26. 26.🔋 Does a washing machine give electricity or use electricity? (a) gives electricity (b) uses electricity
  27. 27.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) wavy lines (c) straight lines (d) dotted circles
  28. 28.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) a fuse (c) an output (d) an input
  29. 29.🧩 Which component is a resistance knob? (a) potentiometer (b) thermistor (c) transistor (d) resistor
  30. 30.True or false: “a motion sensor signal” is the process. (a) True (b) False
  31. 31.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  32. 32.True or false: to open a phone charger is not safe. (a) False (b) True
  33. 33.🔐 Who should decide which smart devices go in a child’s room? (a) nobody at all (b) an online stranger (c) a parent or guardian (d) the app’s adverts
  34. 34.What does an LED do? (a) turns a fan or wheels (b) blows if current is high (c) makes things spin (d) glows using little power
  35. 35.🌈 A resistor has the colour bands green, blue, orange. What is its value in kilo-ohms (kΩ)? =
  36. 36.🌈 In the resistor colour code, which number does white stand for?
  37. 37.True or false: a safety pin is a conductor. (a) False (b) True
  38. 38.🔘 Which kind of switch works only while pressed? (a) a slide switch (b) a reed switch (c) a push button (d) a tilt switch
  39. 39.⚡ A device works on 1.5 V and takes 0.2 A. What is its power (in watts)? =
  40. 40.🔺 A 7.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =

Answer key

  1. bigger
  2. turn to an exact angle
  3. 6
  4. porch lamp ON
  5. True
  6. poke things in a socket
  7. not safe
  8. R = V ÷ I
  9. 3
  10. light energy
  11. wastes electricity
  12. risky habit
  13. True
  14. + (positive)
  15. open a phone charger
  16. current
  17. closed
  18. count button presses
  19. I = V ÷ R
  20. saves electricity
  21. False
  22. a conductor
  23. movement energy
  24. False
  25. adds 1 to count
  26. uses electricity
  27. straight lines
  28. an input
  29. potentiometer
  30. False
  31. anode (+)
  32. True
  33. a parent or guardian
  34. glows using little power
  35. 56
  36. 9
  37. True
  38. a push button
  39. 0.3
  40. 1.5

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