Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 992 · 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: to accept every permission is a risky habit. (a) False (b) True
2. 2.🔌 Is a water pump an input or an output for a microcontroller? (a) output (b) input
3. 3.⚠️ Is it safe to poke things in a socket? (a) safe (b) not safe
4. 4.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
5. 5.🔍 Which is the odd one out? (a) cover unused cameras (b) turn off unused gadgets (c) ignore update messages (d) set up with a parent
6. 6.True or false: an iron nail is a conductor. (a) True (b) False
7. 7.True or false: to turn off unused gadgets is a good habit. (a) False (b) True
8. 8.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) in parallel (c) by Wi-Fi (d) not joined
9. 9.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 LOW
   set pin 7 HIGH
   set pin 7 LOW
   set pin 7 HIGH
   Is the LED ON or OFF at the end? (a) ON (b) OFF
10. 10.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
11. 11.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
12. 12.⚡ Which formula gives electric power? (a) P = V + I (b) P = I ÷ V (c) P = V ÷ I (d) P = V × I
13. 13.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
14. 14.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
15. 15.What does the phone app do? (a) acts on a command (b) shows data to you (c) stores data online (d) reads values, decides
16. 16.🔌 Is aluminium foil a conductor or an insulator? (a) a conductor (b) an insulator
17. 17.True or false: a plastic ruler is a conductor. (a) True (b) False
18. 18.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
19. 19.True or false: one tall, one short bar is the symbol for a bulb. (a) False (b) True
20. 20.💡 2 identical bulbs are joined in series with a 2 V battery (ideal wires). How many volts does each bulb get? =
21. 21.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a plug top (b) a fuse or MCB (c) a long wire (d) a bulb
22. 22.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
23. 23.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
24. 24.🧮 A 20 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
25. 25.True or false: “one out, the rest glow” is true of a parallel circuit. (a) False (b) True
26. 26.🔋 Does a refrigerator give electricity or use electricity? (a) uses electricity (b) gives electricity
27. 27.🔺 A current of 20 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
28. 28.True or false: a dot where wires meet is the symbol for a junction. (a) False (b) True
29. 29.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
30. 30.🤖 if (temperature > 25) { fan ON } else { fan OFF }
    The temperature sensor reads 32 °C. What happens? (a) fan ON (b) fan OFF
31. 31.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
32. 32.Which of these mainly gives out light? (a) a ceiling fan (b) a rice cooker (c) an electric iron (d) a torch
33. 33.⚡ A device works on 6 V and takes 0.2 A. What is its power (in watts)? =
34. 34.🤖 “if (A AND B)” is true when … (a) only A is true (b) only B is true (c) both are false (d) both A and B are true
35. 35.🔗 Series or parallel circuit: “a break stops every bulb”? (a) parallel (b) series
36. 36.⚡ A cell changes stored chemical energy into which kind of energy? (a) wind energy (b) nuclear energy (c) electrical energy (d) sound energy
37. 37.🔍 Which is the odd one out? (a) use LED lamps (b) switch off empty rooms (c) set the AC to 24 °C (d) leave the TV on standby
38. 38.Which drawing is the symbol for a cell? (a) a straight line (b) triangle, bar and arrows (c) a plain rectangle (d) a long and a short line
39. 39.⚡ What does a loudspeaker mainly change electricity into? (a) light (b) movement (c) heat (d) sound
40. 40.Which of these is the input? (a) compare with a limit (b) check if temp > 30 (c) the pump turns on (d) a motion sensor signal

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