Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 249 · 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.✏️ In a circuit diagram, which part is drawn as a circle with V inside? (a) motor (b) voltmeter (c) bulb (d) resistor
2. 2.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) zero (d) bigger
3. 3.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
4. 4.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) in parallel (d) by Wi-Fi
5. 5.⚡ What does a room heater mainly change electricity into? (a) sound (b) movement (c) light (d) heat
6. 6.True or false: on a cell, “the flat end” means the + (positive) end. (a) False (b) True
7. 7.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
   The temperature is 36 °C. What is shown? (a) Warm (b) Cool (c) Hot
8. 8.🔐 Is it a good or a risky habit to cover unused cameras? (a) good habit (b) risky habit
9. 9.🔋 8 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
10. 10.🔘 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 ON and B is OFF. Does the bulb glow? (a) No (b) Yes
11. 11.True or false: a plain rectangle is the symbol for an ammeter. (a) True (b) False
12. 12.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
13. 13.✏️ In a circuit diagram, which part is drawn as a straight line? (a) junction (b) bulb (c) wire (d) battery
14. 14.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) both parts (c) neither part (d) the else part
15. 15.True or false: a motor turns a fan or wheels. (a) False (b) True
16. 16.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
17. 17.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) changes the voltage (c) makes electricity (d) stores current
18. 18.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) waits 500 seconds (c) pauses for half a second (d) turns the LED off
19. 19.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
20. 20.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 25 % (c) 5 % (d) 50 %
21. 21.🌈 Which band is read first on a resistor? (a) any band (b) the widest gap (c) the one nearest an end (d) the gold band
22. 22.🔺 A current of 25 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
23. 23.Which job needs a servo motor? (a) turn to an exact angle (b) spin a robot’s wheels (c) show a status light (d) beep an alarm
24. 24.Which of these is not safe? (a) dry your hands first (b) stay away from pylons (c) touch a switch when wet (d) build with an adult near
25. 25.🔺 A current of 0.1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🔋 How many 1.5 V cells must be joined in series to give 4.5 V?
27. 27.🌐 What does IoT stand for? (a) Internet of Talk (b) Internet of Things (c) Input of Tools (d) Inside of Toys
28. 28.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
29. 29.Which of these mainly makes movement? (a) a traffic signal (b) an electric drill (c) a siren (d) a school bell
30. 30.⚡ A device works on 24 V and takes 0.2 A. What is its power (in watts)? =
31. 31.🔍 Which is the odd one out? (a) accept every permission (b) reuse one password (c) share only needed data (d) keep factory passwords
32. 32.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to limit the current (c) to change its colour (d) to store charge
33. 33.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) the switch is OFF (d) all wires are joined
34. 34.True or false: on an LED, the leg by the flat edge is the anode (+). (a) True (b) False
35. 35.🔺 A current of 40 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
36. 36.🌈 A resistor has the colour bands grey, grey, brown. What is its value (in ohms)?
37. 37.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
38. 38.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I × R (d) V = I ÷ R
39. 39.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
40. 40.⚡ What does a buzzer mainly change electricity into? (a) heat (b) light (c) sound (d) movement

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