← Final electronics test lesson New set →

Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 912 · 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.

NameDateTime takenScore ___ / 40
  1. 1.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
  2. 2.True or false: a laptop has no screen of its own. (a) True (b) False
  3. 3.🔁 count = 9
    repeat 3 times { count = count + 9 }
    What is count at the end?
  4. 4.🔁 count = 5
    while (count < 26) { count = count + 3 }
    How many times does the loop run?
  5. 5.Which of these is safe? (a) use mains for a project (b) stay away from pylons (c) open a phone charger (d) poke things in a socket
  6. 6.🤖 Does a digital alarm clock usually have a microcontroller inside? (a) No (b) Yes
  7. 7.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  8. 8.What does a push button do? (a) closes near a magnet (b) springs back when let go (c) flips up or down (d) stays where you flip it
  9. 9.🔺 A current of 40 mA flows when 8 V is joined across a resistor. What is its resistance (in ohms)?
  10. 10.💡 2 identical bulbs are joined in parallel across a 4.5 V battery (ideal wires). How many volts does each bulb get? =
  11. 11.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 4 seconds?
  12. 12.📏 How many milliamperes (mA) is 2.13 A?
  13. 13.True or false: a copper wire is an insulator. (a) False (b) True
  14. 14.🤖 “if (A AND B)” is true when … (a) only A is true (b) only B is true (c) both A and B are true (d) both are false
  15. 15.Which of these is a good habit? (a) share camera links (b) keep factory passwords (c) tap unknown app links (d) install software updates
  16. 16.🔺 A 2.4 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  17. 17.🔋 How many volts does one ordinary torch cell give? (a) 230 V (b) 0.5 V (c) 15 V (d) 1.5 V
  18. 18.True or false: a straight line is the symbol for a cell. (a) False (b) True
  19. 19.🔁 count = 5
    while (count < 14) { count = count + 3 }
    How many times does the loop run?
  20. 20.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
  21. 21.🔌 Is a plastic ruler a conductor or an insulator? (a) an insulator (b) a conductor
  22. 22.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 100 (c) 10 (d) 1000
  23. 23.💡 An LED is joined to a 5 V battery through a 470 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) may burn out (c) lights up
  24. 24.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  25. 25.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
  26. 26.🔍 Which is the odd one out? (a) a graphite rod (b) a steel coin (c) a brass key (d) a paper strip
  27. 27.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) stay the same (c) smaller (d) zero
  28. 28.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) No (b) Yes
  29. 29.🔍 Which sensor would you use to keep an incubator warm? (a) a temperature sensor (b) a soil moisture sensor (c) a gas sensor (d) a rain sensor
  30. 30.Which of these is the process? (a) a soil moisture reading (b) a buzzer beeps (c) check if temp > 30 (d) an alert on the phone
  31. 31.🔁 x = 4
    repeat 4 times { x = x × 2 }
    What is x at the end?
  32. 32.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 5 % (d) 25 %
  33. 33.🔐 Why install updates on IoT devices? (a) they change the colour (b) they fix security holes (c) they delete the Wi-Fi (d) they make it heavier
  34. 34.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) leave fridge door open (d) unplug idle chargers
  35. 35.What does a diode do? (a) lets current go one way (b) senses how bright it is (c) turns a fan or wheels (d) beeps for an alarm
  36. 36.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  37. 37.Which of these is measured in amperes (A)? (a) the flow of charge (b) how much a part resists (c) resistance (d) energy used each second
  38. 38.True or false: “many paths for current” is true of a series circuit. (a) False (b) True
  39. 39.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end?     (a) ON (b) OFF
  40. 40.🤖 Does a bicycle bell usually have a microcontroller inside? (a) No (b) Yes

Answer key

  1. 2300
  2. False
  3. 36
  4. 7
  5. stay away from pylons
  6. Yes
  7. open
  8. springs back when let go
  9. 200
  10. 4.5
  11. 4
  12. 2130
  13. False
  14. both A and B are true
  15. install software updates
  16. 0.2
  17. 1.5 V
  18. False
  19. 3
  20. − (negative)
  21. an insulator
  22. 1000
  23. lights up
  24. anode (+)
  25. True
  26. a paper strip
  27. bigger
  28. No
  29. a temperature sensor
  30. check if temp > 30
  31. 64
  32. 5 %
  33. they fix security holes
  34. unplug idle chargers
  35. lets current go one way
  36. closed
  37. the flow of charge
  38. False
  39. ON
  40. No

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids