Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 95 · 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.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) sets count to 1 (c) takes 1 away (d) prints 1
2. 2.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 15000 Ω resistor? (a) brown-green-orange (b) brown-green-yellow (c) brown-green-red (d) green-brown-orange
3. 3.🔺 A current of 20 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔌 Most metals are good … (a) insulators (b) magnets only (c) conductors (d) batteries
5. 5.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 LOW
   set pin 7 HIGH
   set pin 7 LOW
   set pin 8 HIGH
   Is the LED ON or OFF at the end? (a) OFF (b) ON
6. 6.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
7. 7.True or false: a potentiometer blows if current is high. (a) False (b) True
8. 8.🧮 A 1.2 V battery is joined to 2 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
9. 9.Which of these wastes electricity? (a) set the AC to 24 °C (b) use LED lamps (c) use old filament bulbs (d) switch off empty rooms
10. 10.🧭 Which part of a microcontroller board brings power and code? (a) the power LED (b) the voltage regulator (c) the USB port (d) the reset button
11. 11.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
12. 12.Which of these is not an IoT device? (a) a Wi-Fi weather station (b) a Wi-Fi smart plug (c) a smart energy meter (d) a battery torch
13. 13.⚡ A 9 W device works on 3 V. What current does it take (in amperes)? =
14. 14.📏 Voltmeter or ammeter: which one measures current? (a) ammeter (b) voltmeter
15. 15.⚡ A device works on 12 V and takes 0.2 A. What is its power (in watts)? =
16. 16.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
17. 17.🔁 x = 1
    repeat 4 times { x = x × 2 }
    What is x at the end?
18. 18.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 volt (d) 1 kilowatt-hour (kWh)
19. 19.🤖 Does a hand pump usually have a microcontroller inside? (a) Yes (b) No
20. 20.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 5 % (c) 50 % (d) 0 %
21. 21.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) pick a problem to solve (b) build it with an adult (c) test it and fix it (d) list inputs and outputs
22. 22.🌐 In an IoT system, which part shows data to you? (a) cloud server (b) actuator (c) Wi-Fi (d) phone app
23. 23.📏 Which unit measures resistance? (a) ampere (A) (b) volt (V) (c) ohm (Ω) (d) watt (W)
24. 24.💡 In a series circuit, how many paths does the current have? (a) one (b) one for each bulb (c) two (d) none
25. 25.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
26. 26.Which of these is a conductor? (a) a safety pin (b) a rubber band (c) a cotton thread (d) a ceramic cup
27. 27.💡 An LED is joined to a 5 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) lights up (c) may burn out
28. 28.🔍 Which is the odd one out? (a) share the Wi-Fi key (b) turn off unused gadgets (c) ignore update messages (d) accept every permission
29. 29.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is OFF and B is ON. Does the bulb glow? (a) No (b) Yes
30. 30.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
31. 31.⚡ A device works on 3 V and takes 3 A. What is its power (in watts)? =
32. 32.Which of these mainly gives out heat? (a) a doorbell (b) a rice cooker (c) a table fan (d) a siren
33. 33.True or false: a toy robot usually has a microcontroller inside. (a) False (b) True
34. 34.🔍 Which is the odd one out? (a) read app permissions (b) change default passwords (c) keep factory passwords (d) log out of shared phones
35. 35.True or false: a reed switch closes when tipped over. (a) True (b) False
36. 36.🔍 Which is the odd one out? (a) a light level reading (b) a buzzer beeps (c) a button press (d) a temperature reading
37. 37.True or false: a microcontroller runs many apps at once. (a) False (b) True
38. 38.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
39. 39.True or false: to unplug idle chargers saves electricity. (a) False (b) True
40. 40.🧩 Which component senses how bright it is? (a) LDR (b) transistor (c) diode (d) resistor

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