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Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 568 · 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.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a buzzer (c) a capacitor (d) a diode
  2. 2.Which drawing is the symbol for a battery? (a) a straight line (b) one tall, one short bar (c) two or more cell symbols (d) a plain rectangle
  3. 3.🌈 A resistor has the colour bands green, yellow, red. What is its value in kilo-ohms (kΩ)? =
  4. 4.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put an iron nail across the gap. Does the bulb glow? (a) Yes (b) No
  5. 5.True or false: a push button works only while pressed. (a) False (b) True
  6. 6.🔍 Which is the odd one out? (a) a mixer grinder (b) a buzzer (c) an electric drill (d) a ceiling fan
  7. 7.⚡ A device works on 12 V and takes 0.5 A. What is its power (in watts)? =
  8. 8.🔍 Which is the odd one out? (a) an alert on the phone (b) a soil moisture reading (c) a temperature reading (d) a light level reading
  9. 9.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
  10. 10.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 2.75 V supply. What current flows (in mA)?
  11. 11.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) not joined (d) in series
  12. 12.🔁 x = 1
    repeat 2 times { x = x × 2 }
    What is x at the end?
  13. 13.🔍 Which is the odd one out? (a) a battery torch (b) a fitness band with app (c) a plain wall switch (d) a pencil sharpener
  14. 14.🔘 A bulb and a cell are joined through 4 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
  15. 15.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 300 ms }
    How many milliseconds does one blink (ON + OFF) take?
  16. 16.🔌 Most metals are good … (a) batteries (b) magnets only (c) conductors (d) insulators
  17. 17.Which of these is an insulator? (a) a copper wire (b) an iron nail (c) a paper strip (d) a safety pin
  18. 18.🔌 Which part of a screwdriver should an electrician hold? (a) the metal tip (b) the plastic handle (c) the steel shaft (d) the bare end
  19. 19.🌐 Is a pencil sharpener an IoT device? (a) not an IoT device (b) an IoT device
  20. 20.🧩 Which part changes electrical energy into movement? (a) an LED (b) a fuse (c) a resistor (d) a motor
  21. 21.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
  22. 22.What does a push button do? (a) closes when tipped over (b) works only while pressed (c) closes near a magnet (d) stays where you flip it
  23. 23.🗺️ In an input → process → output plan, is “check if temp > 30” the input, the process or the output? (a) process (b) input (c) output
  24. 24.🔺 A 16 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
  25. 25.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
  26. 26.⏱️ A program says “wait 3000 ms”. How many seconds is that? =
  27. 27.⚡ A 2.5 W device works on 5 V. What current does it take (in amperes)? =
  28. 28.🔋 6 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
  29. 29.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 12 V (c) 1.5 V (d) 9 V
  30. 30.Which of these is the output? (a) a soil moisture reading (b) a light level reading (c) a buzzer beeps (d) a temperature reading
  31. 31.🔘 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 OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
  32. 32.🔺 A current of 40 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
  33. 33.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
  34. 34.🔺 A current of 50 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
  35. 35.🤖 Does a digital alarm clock usually have a microcontroller inside? (a) No (b) Yes
  36. 36.⚡ A fan changes electrical energy mainly into which kind of energy? (a) movement energy (b) light energy (c) chemical energy (d) sound energy
  37. 37.True or false: “the fan starts” is the input. (a) False (b) True
  38. 38.Which of these is measured in volts (V)? (a) how much a part resists (b) resistance (c) current (d) voltage
  39. 39.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) Yes (b) No
  40. 40.⏱️ A program says “wait 6250 ms”. How many seconds is that? =

Answer key

  1. a buzzer
  2. two or more cell symbols
  3. 5.4
  4. Yes
  5. True
  6. a buzzer
  7. 6
  8. an alert on the phone
  9. False
  10. 5
  11. in series
  12. 4
  13. a fitness band with app
  14. 4
  15. 700
  16. conductors
  17. a paper strip
  18. the plastic handle
  19. not an IoT device
  20. a motor
  21. False
  22. works only while pressed
  23. process
  24. 40
  25. + (positive)
  26. 3
  27. 0.5
  28. 9
  29. 230 V
  30. a buzzer beeps
  31. No
  32. 20
  33. wastes electricity
  34. 10
  35. Yes
  36. movement energy
  37. False
  38. voltage
  39. Yes
  40. 6.25

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