Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 215 · 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.🔁 count = 1
   repeat 6 times { count = count + 9 }
   What is count at the end?
2. 2.🌈 In the resistor colour code, which number does red stand for?
3. 3.True or false: a graphite rod is a conductor. (a) True (b) False
4. 4.🌈 A resistor has the colour bands brown, blue, red. What is its value in kilo-ohms (kΩ)? =
5. 5.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) so all go off together (d) to make bulbs dim
6. 6.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a series circuit (d) a closed circuit
7. 7.🔌 Which metal is used for most electric wires at home? (a) plastic (b) rubber (c) copper (d) glass
8. 8.Which job needs a pump? (a) show the temperature (b) beep an alarm (c) move water to plants (d) show a status light
9. 9.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
10. 10.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they all go out (c) they get dimmer (d) they keep glowing
11. 11.🔺 A current of 1.5 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.📏 In the water-pipe picture of a circuit, resistance is like … (a) a bigger tank (b) the flow of water (c) the water pressure (d) a narrow pipe
13. 13.True or false: the ammeter is joined in series. (a) False (b) True
14. 14.📏 How many amperes (A) is 1830 mA? =
15. 15.What does a motor do? (a) glows using little power (b) makes a beeping sound (c) turns a fan or wheels (d) has coloured bands
16. 16.Which of these is safe? (a) touch a fallen wire (b) touch a switch when wet (c) stay away from pylons (d) use a cable with cuts
17. 17.📏 Which unit measures how much a part resists? (a) ampere (A) (b) volt (V) (c) ohm (Ω) (d) watt (W)
18. 18.🔋 Identical cells side by side (in parallel) give … (a) the same voltage (b) no voltage (c) double the voltage (d) half the voltage
19. 19.💡 An LED is joined to a 6 V battery through a 1000 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) lights up (c) may burn out
20. 20.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 470 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
21. 21.🔁 count = 0
    while (count < 35) { count = count + 5 }
    How many times does the loop run?
22. 22.🔁 count = 1
    while (count < 41) { count = count + 5 }
    How many times does the loop run?
23. 23.Which drawing is the symbol for a junction? (a) a plain rectangle (b) two equal parallel lines (c) a dot where wires meet (d) one tall, one short bar
24. 24.🔍 Which is the odd one out? (a) a rubber eraser (b) a brass key (c) a plastic ruler (d) a ceramic cup
25. 25.📶 A pin set LOW gives about … (a) 0 V (b) 9 V (c) 1.5 V (d) 5 V
26. 26.🧮 A 2 V battery is joined to 6 Ω and 2 Ω resistors in series. What current flows (in amperes)? =
27. 27.Which of these is an insulator? (a) a brass key (b) a woollen thread (c) an iron nail (d) a safety pin
28. 28.⏱️ repeat 7 times { buzzer ON; wait 500 ms; buzzer OFF; wait 300 ms }
    How many milliseconds does this take in all?
29. 29.💡 5 identical bulbs are joined in series with a 12.5 V battery (ideal wires). How many volts does each bulb get? =
30. 30.🌈 In the resistor colour code, which number does grey stand for?
31. 31.🤖 if (temperature > 38) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 17 °C. What is shown? (a) Cool (b) Hot (c) Warm
32. 32.🔍 Which sensor would you use to measure classroom noise? (a) a light sensor (b) a soil moisture sensor (c) a sound sensor (d) a motion sensor
33. 33.🌈 A resistor has the colour bands yellow, white, black. What is its value (in ohms)?
34. 34.🔍 Which is the odd one out? (a) use a cable with cuts (b) touch a fallen wire (c) open a phone charger (d) dry your hands first
35. 35.True or false: energy used each second is measured in volts (V). (a) True (b) False
36. 36.True or false: a long and a short line is the symbol for a cell. (a) True (b) False
37. 37.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) blinks 500 times (c) waits 500 seconds (d) pauses for half a second
38. 38.🔍 Which is the odd one out? (a) touch a switch when wet (b) climb an electric pole (c) throw cells in a fire (d) stay away from pylons
39. 39.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
40. 40.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =

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