Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 533 · 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.Which of these mainly gives out light? (a) a tube light (b) a rice cooker (c) an exhaust fan (d) an electric iron
2. 2.True or false: “used in house wiring” is true of a parallel circuit. (a) True (b) False
3. 3.True or false: to leave fridge door open saves electricity. (a) True (b) False
4. 4.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber eraser across the gap. Does the bulb glow? (a) Yes (b) No
5. 5.🔁 repeat 6 times { repeat 3 times { beep } }
   How many beeps are there?
6. 6.🧮 A 68 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
7. 7.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
8. 8.🔁 total = 0
   for i = 1 to 10 { total = total + i }
   What is total at the end?
9. 9.🔺 A current of 0.1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
10. 10.🤖 Which is a safe power source for a beginner microcontroller board? (a) USB or a 9 V battery (b) a 230 V cable (c) bare mains wires (d) a wall socket directly
11. 11.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a full circuit (d) a closed circuit
12. 12.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) adds 1 to count (d) prints 1
13. 13.True or false: to tap unknown app links is a good habit. (a) True (b) False
14. 14.⏱️ repeat 6 times { buzzer ON; wait 700 ms; buzzer OFF; wait 700 ms }
    How many milliseconds does this take in all?
15. 15.🔁 count = 5
    while (count < 29) { count = count + 4 }
    How many times does the loop run?
16. 16.Which of these gives us electricity? (a) an air conditioner (b) a solar panel (c) a water pump (d) a mobile phone
17. 17.🔺 A 20 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
18. 18.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the switch is ON (d) the loop is complete
19. 19.Which of these is not an IoT device? (a) a fitness band with app (b) a pencil sharpener (c) a Wi-Fi doorbell camera (d) a Wi-Fi smart plug
20. 20.Which of these is a good habit? (a) share the Wi-Fi key (b) accept every permission (c) share camera links (d) log out of shared phones
21. 21.🗺️ In an input → process → output plan, is “the pump turns on” the input, the process or the output? (a) process (b) output (c) input
22. 22.💡 An LED is joined to a 6 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) may burn out (c) lights up
23. 23.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) neither part (c) the else part (d) the if part
24. 24.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 540 Ω resistor? (a) green-yellow-brown (b) yellow-green-brown (c) green-yellow-black (d) green-yellow-red
25. 25.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the cloud stores it (b) it is sent by Wi-Fi (c) the app shows it (d) the sensor measures
26. 26.Which of these is not safe? (a) use mains for a project (b) build with an adult near (c) keep drinks far away (d) fly kites in open fields
27. 27.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = I ÷ V (c) R = V + I (d) R = V × I
28. 28.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) Yes (b) No
29. 29.Which of these means the circuit is open? (a) the loop is complete (b) the switch is OFF (c) the switch is ON (d) all wires are joined
30. 30.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 5 V supply. What current flows (in mA)?
31. 31.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 5 % (c) 50 % (d) 25 %
32. 32.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) Yes (b) No
33. 33.📏 Voltmeter or ammeter: which one is joined in series? (a) ammeter (b) voltmeter
34. 34.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
35. 35.🔁 repeat 3 times { repeat 4 times { beep } }
    How many beeps are there?
36. 36.⏱️ loop forever { LED ON; wait 550 ms; LED OFF; wait 300 ms }
    How many milliseconds does one blink (ON + OFF) take?
37. 37.Which of these is a conductor? (a) a paper strip (b) a plastic ruler (c) aluminium foil (d) a woollen thread
38. 38.True or false: “an LED lights up” is the output. (a) True (b) False
39. 39.🔍 Which is the odd one out? (a) compare with a limit (b) an LED lights up (c) the pump turns on (d) a buzzer beeps
40. 40.What does a motor do? (a) stores a little charge (b) turns a fan or wheels (c) boosts a small signal (d) limits the current

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