Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 523 · 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.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) battery (b) motor (c) bulb (d) capacitor
2. 2.🧮 Five equal 250 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
3. 3.💡 2 identical bulbs are joined in parallel across a 9 V battery (ideal wires). How many volts does each bulb get? =
4. 4.True or false: to leave the TV on standby saves electricity. (a) False (b) True
5. 5.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
6. 6.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 8 LOW
   set pin 7 HIGH
   set pin 8 LOW
   set pin 8 HIGH
   set pin 7 HIGH
   Is the LED ON or OFF at the end? (a) OFF (b) ON
7. 7.🔺 A current of 25 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
8. 8.🤖 if (moisture < 30) { pump ON } else { pump OFF }
   The soil moisture sensor reads 11 %. What happens? (a) pump ON (b) pump OFF
9. 9.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
10. 10.🔌 Is a motor an input or an output for a microcontroller? (a) output (b) input
11. 11.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 6 V supply. What current flows (in mA)?
12. 12.🔍 Which is the odd one out? (a) turn off unused gadgets (b) read app permissions (c) install software updates (d) accept every permission
13. 13.Which of these saves electricity? (a) leave the TV on standby (b) switch off empty rooms (c) run fans in empty rooms (d) iron one shirt at a time
14. 14.🔺 A current of 2.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
15. 15.⚠️ Is it safe to keep drinks far away? (a) not safe (b) safe
16. 16.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 1.5 V (c) 0.5 V (d) 230 V
17. 17.Which of these is safe? (a) take cells out after use (b) use mains for a project (c) climb an electric pole (d) throw cells in a fire
18. 18.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) a power source (c) an input (d) an output
19. 19.Which drawing is the symbol for a diode? (a) triangle against a bar (b) many long-short pairs (c) a circle with V inside (d) one tall, one short bar
20. 20.🔘 Which kind of switch works only while pressed? (a) a toggle switch (b) a slide switch (c) a tilt switch (d) a push button
21. 21.🤖 if (distance < 15) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 15 cm. What happens? (a) buzzer beeps (b) buzzer is silent
22. 22.📶 A pin set LOW gives about … (a) 9 V (b) 1.5 V (c) 5 V (d) 0 V
23. 23.🤖 if (distance < 20) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 21 cm. What happens? (a) buzzer is silent (b) buzzer beeps
24. 24.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a candle (c) an LED lamp (d) a filament bulb
25. 25.🔺 A 2 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
26. 26.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the process (b) the battery (c) the input (d) the output
27. 27.🔍 Which is the odd one out? (a) keep factory passwords (b) install software updates (c) share the Wi-Fi key (d) post your live location
28. 28.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
29. 29.Which job is done by the main chip? (a) keeps the voltage steady (b) restarts the program (c) brings power and code (d) runs the program
30. 30.True or false: two or more cell symbols is the symbol for a battery. (a) True (b) False
31. 31.What does the sensor do? (a) reads values, decides (b) acts on a command (c) measures the real world (d) carries the data
32. 32.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
33. 33.True or false: a small empty box is the symbol for a wire. (a) True (b) False
34. 34.Which job needs an LED? (a) move water to plants (b) beep an alarm (c) open a gate to 90° (d) show a status light
35. 35.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 48000 Ω resistor? (a) yellow-grey-yellow (b) yellow-grey-orange (c) yellow-grey-red (d) grey-yellow-orange
36. 36.💡 Why does an LED need a resistor in series? (a) to store charge (b) to limit the current (c) to change its colour (d) to make it brighter
37. 37.🔍 Which is the odd one out? (a) a buzzer (b) a school bell (c) an electric kettle (d) a doorbell
38. 38.Which drawing is the symbol for an ammeter? (a) a circle with A inside (b) a plain rectangle (c) two or more cell symbols (d) many long-short pairs
39. 39.True or false: a toaster mainly gives out heat. (a) False (b) True
40. 40.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) when either is ON (c) only when both are OFF (d) never

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