Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 146 · 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.🔋 Identical cells side by side (in parallel) give … (a) no voltage (b) half the voltage (c) the same voltage (d) double the voltage
2. 2.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
3. 3.🧩 Which component makes a beeping sound? (a) thermistor (b) transistor (c) buzzer (d) LED
4. 4.Which of these is a risky habit? (a) set a strong password (b) share only needed data (c) reuse one password (d) turn off unused gadgets
5. 5.True or false: a laptop runs many apps at once. (a) False (b) True
6. 6.🔍 Which is the odd one out? (a) leave fridge door open (b) iron one shirt at a time (c) use LED lamps (d) leave the TV on standby
7. 7.🔺 A current of 2 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
8. 8.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) in series (c) in parallel (d) not joined
9. 9.Which of these is an insulator? (a) a safety pin (b) a brass key (c) a copper wire (d) a paper strip
10. 10.🔍 Which is the odd one out? (a) post your live location (b) keep factory passwords (c) ignore update messages (d) change default passwords
11. 11.🗺️ In an input → process → output plan, is “an LED lights up” the input, the process or the output? (a) input (b) process (c) output
12. 12.True or false: triangle against a bar is the symbol for a bulb. (a) True (b) False
13. 13.🔋 What is a battery? (a) a kind of bulb (b) one single wire (c) two or more cells joined (d) a switch with a lid
14. 14.🔁 x = 4
    repeat 3 times { x = x × 2 }
    What is x at the end?
15. 15.True or false: two or more cell symbols is the symbol for a motor. (a) False (b) True
16. 16.🔍 Which is the odd one out? (a) fly a kite near wires (b) fly kites in open fields (c) stop if a part gets hot (d) keep drinks far away
17. 17.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) stores a value (d) joins two wires
18. 18.True or false: current is measured in ohms (Ω). (a) False (b) True
19. 19.True or false: to keep an incubator warm, use a rain sensor. (a) False (b) True
20. 20.🔌 Is a ceramic cup a conductor or an insulator? (a) a conductor (b) an insulator
21. 21.What does a tilt switch do? (a) closes near a magnet (b) closes when tipped over (c) stays where you flip it (d) springs back when let go
22. 22.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
23. 23.What does an LED do? (a) smooths a wobbly supply (b) limits the current (c) glows using little power (d) makes things spin
24. 24.🤖 What is a microcontroller? (a) a kind of bulb (b) a big desktop computer (c) a type of battery (d) a computer on one chip
25. 25.🌈 In the resistor colour code, which number does grey stand for?
26. 26.🔺 A 10 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
27. 27.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) a candle (c) an LED lamp (d) an oil lamp
28. 28.🔍 Which is the odd one out? (a) a paper strip (b) a rubber band (c) a ceramic cup (d) an iron nail
29. 29.⏱️ repeat 10 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 700 ms }
    How many milliseconds does this take in all?
30. 30.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 42 %. What happens? (a) pump ON (b) pump OFF
31. 31.🔐 Is it a good or a risky habit to turn off unused gadgets? (a) risky habit (b) good habit
32. 32.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire has come loose (d) the switch is ON
33. 33.🔍 Which is the odd one out? (a) a button press (b) a soil moisture reading (c) a temperature reading (d) count button presses
34. 34.🌈 A resistor has the colour bands green, black, orange. What is its value (in ohms)?
35. 35.💡 In a series circuit, how many paths does the current have? (a) two (b) none (c) one for each bulb (d) one
36. 36.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
37. 37.Which of these mainly gives out light? (a) a torch (b) a toaster (c) a siren (d) an electric drill
38. 38.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 850 ms }
    How many milliseconds does one blink (ON + OFF) take?
39. 39.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
40. 40.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe

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