Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 680 · 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.What does a push button do? (a) stays where you flip it (b) closes when tipped over (c) flips up or down (d) springs back when let go
2. 2.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is OFF (d) the switch is ON
4. 4.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
5. 5.Which of these is a risky habit? (a) read app permissions (b) ignore update messages (c) cover unused cameras (d) set a strong password
6. 6.🔋 A 12 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
7. 7.🌈 A resistor has the colour bands brown, violet, black. What is its value (in ohms)?
8. 8.⚠️ Is it safe to throw cells in a fire? (a) not safe (b) safe
9. 9.⏱️ How many milliseconds is a wait of 2.5 seconds?
10. 10.Which of these is measured in ohms (Ω)? (a) the push of a cell (b) voltage (c) resistance (d) current
11. 11.⏱️ A program says “wait 3500 ms”. How many seconds is that? =
12. 12.Which of these is a conductor? (a) a wooden stick (b) a plastic ruler (c) a brass key (d) a rubber band
13. 13.⚠️ Is it safe to climb an electric pole? (a) not safe (b) safe
14. 14.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets smaller (d) gets bigger
15. 15.⚡ What does an exhaust fan mainly change electricity into? (a) movement (b) sound (c) light (d) heat
16. 16.What does a slide switch do? (a) slides side to side (b) flips up or down (c) stays where you flip it (d) springs back when let go
17. 17.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
18. 18.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to an 8 V supply. What current flows (in mA)?
19. 19.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.🔺 A current of 50 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
21. 21.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
22. 22.🔘 Which kind of switch works only while pressed? (a) a toggle switch (b) a reed switch (c) a push button (d) a slide switch
23. 23.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
24. 24.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
25. 25.🔺 A current of 40 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🔋 A 9 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
27. 27.Which of these is a risky habit? (a) set a strong password (b) turn off unused gadgets (c) read app permissions (d) keep factory passwords
28. 28.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
29. 29.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it does not light (c) it changes colour (d) it makes a sound
30. 30.Which of these is safe? (a) build with an adult near (b) use mains for a project (c) touch a switch when wet (d) open a phone charger
31. 31.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
32. 32.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) movement energy (b) light energy (c) chemical energy (d) sound energy
33. 33.Which drawing is the symbol for a cell? (a) triangle against a bar (b) a dot where wires meet (c) two or more cell symbols (d) one tall, one short bar
34. 34.Which drawing is the symbol for a battery? (a) a circle with a cross (b) one tall, one short bar (c) a circle with an X in it (d) two or more cell symbols
35. 35.True or false: “own switch for each bulb” is true of a series circuit. (a) False (b) True
36. 36.🔌 Is a safety pin a conductor or an insulator? (a) an insulator (b) a conductor
37. 37.Which of these saves electricity? (a) use old filament bulbs (b) use LED lamps (c) leave fridge door open (d) leave the TV on standby
38. 38.True or false: a woollen thread is a conductor. (a) False (b) True
39. 39.True or false: to keep an incubator warm, use a sound sensor. (a) False (b) True
40. 40.🤖 if (sound > 70) { red LED ON } else { green LED ON }
    The sound sensor reads 86. What happens? (a) red LED ON (b) green LED ON

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