Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 595 · 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.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) stay the same (d) smaller
2. 2.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 10 (b) 1000 (c) 100 (d) 1024
3. 3.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
4. 4.🔺 A 9 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
5. 5.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a safe circuit (b) a parallel circuit (c) an open circuit (d) a short circuit
6. 6.🧩 Which component blows if current is high? (a) capacitor (b) thermistor (c) fuse (d) buzzer
7. 7.🔁 x = 3
   repeat 4 times { x = x × 2 }
   What is x at the end?
8. 8.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is ON, C is ON and D is OFF. Does the bulb glow? (a) No (b) Yes
9. 9.💡 5 identical bulbs are joined in series with a 20 V battery (ideal wires). How many volts does each bulb get? =
10. 10.🔁 count = 0
    while (count < 15) { count = count + 5 }
    How many times does the loop run?
11. 11.🔺 A current of 0.1 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
12. 12.Which of these is true of a series circuit? (a) used in house wiring (b) one bulb out, all go out (c) one out, the rest glow (d) each gets the full volts
13. 13.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 kilowatt-hour (kWh) (c) 1 watt (d) 1 volt
14. 14.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
15. 15.True or false: “many paths for current” is true of a series circuit. (a) False (b) True
16. 16.Which of these is a risky habit? (a) change default passwords (b) post your live location (c) set a strong password (d) set up with a parent
17. 17.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a glass marble across the gap. Does the bulb glow? (a) No (b) Yes
18. 18.🌈 A resistor has the colour bands yellow, brown, brown. What is its value (in ohms)?
19. 19.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 9 seconds?
20. 20.🧩 Which component makes a beeping sound? (a) buzzer (b) thermistor (c) fuse (d) capacitor
21. 21.🌐 Is a fitness band with app an IoT device? (a) not an IoT device (b) an IoT device
22. 22.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) a cell is taken out (d) the switch is ON
23. 23.🔺 A current of 0.25 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
24. 24.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) True (b) False
25. 25.📏 Which unit measures current? (a) volt (V) (b) ampere (A) (c) ohm (Ω) (d) watt (W)
26. 26.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V + R (c) I = V ÷ R (d) I = V × R
27. 27.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
28. 28.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is OFF, B is ON, C is ON and D is ON. Does the bulb glow? (a) Yes (b) No
29. 29.⏱️ How many milliseconds is a wait of 1.9 seconds?
30. 30.🔍 Which is the odd one out? (a) use a cable with cuts (b) climb an electric pole (c) build with an adult near (d) throw cells in a fire
31. 31.🔍 Which is the odd one out? (a) a steel spoon (b) a wooden stick (c) a plastic ruler (d) a plastic straw
32. 32.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “wait a few seconds”? (a) read the soil sensor (b) wait a few seconds
33. 33.🔺 An 8 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
34. 34.True or false: a resistor has coloured bands. (a) True (b) False
35. 35.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 200 ms }
    How many milliseconds does one blink (ON + OFF) take?
36. 36.🔗 Series or parallel circuit: “a break stops every bulb”? (a) parallel (b) series
37. 37.📏 How many milliamperes (mA) is 0.83 A?
38. 38.🧩 Which component is a resistance knob? (a) potentiometer (b) LED (c) fuse (d) diode
39. 39.🧭 Which part of a microcontroller board restarts the program? (a) the USB port (b) the reset button (c) the pins (d) the voltage regulator
40. 40.True or false: “a break stops every bulb” is true of a parallel circuit. (a) True (b) False

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