Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 486 · 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 colour bands (1st digit, 2nd digit, multiplier) mark a 290 Ω resistor? (a) red-white-red (b) red-white-brown (c) white-red-brown (d) red-white-black
2. 2.Which of these is true of a series circuit? (a) many paths for current (b) each gets the full volts (c) own switch for each bulb (d) bulbs share the voltage
3. 3.🌈 A resistor has the colour bands violet, green, brown. What is its value (in ohms)?
4. 4.🔋 How many 1.5 V cells must be joined in series to give 9 V?
5. 5.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = R ÷ I (c) V = I ÷ R (d) V = I + R
6. 6.True or false: to keep drinks far away is not safe. (a) True (b) False
7. 7.🔺 A current of 3 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
8. 8.What does a diode do? (a) limits the current (b) makes a beeping sound (c) turns a fan or wheels (d) lets current go one way
9. 9.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in parallel (c) by Wi-Fi (d) in series
10. 10.🔺 A 3 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
11. 11.📏 How many kilowatts (kW) is 3250 W? =
12. 12.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 470 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
13. 13.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets smaller (c) gets bigger (d) becomes zero
14. 14.🔍 Which sensor would you use to close a window in rain? (a) a rain sensor (b) a light sensor (c) a sound sensor (d) a distance sensor
15. 15.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) one out, the rest glow (c) a single current path (d) bulbs share the voltage
16. 16.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
17. 17.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 34 Ω resistor? (a) orange-yellow-black (b) orange-yellow-brown (c) yellow-orange-black (d) yellow-yellow-black
18. 18.🔐 Who should decide which smart devices go in a child’s room? (a) the app’s adverts (b) nobody at all (c) an online stranger (d) a parent or guardian
19. 19.⚡ A 3 W device works on 12 V. What current does it take (in amperes)? =
20. 20.True or false: a TV remote usually has a microcontroller inside. (a) False (b) True
21. 21.🔺 A current of 10 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
22. 22.🔋 A 3 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
23. 23.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = V × I (d) P = I ÷ V
24. 24.⚡ What do we call a flow of electric charge through a wire? (a) friction (b) a magnet (c) electric current (d) sound
25. 25.🌈 A resistor has the colour bands brown, grey, red. What is its value in kilo-ohms (kΩ)? =
26. 26.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a dry cork across the gap. Does the bulb glow? (a) Yes (b) No
27. 27.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
28. 28.🔍 Which is the odd one out? (a) dry your hands first (b) use small battery cells (c) stay away from pylons (d) touch a fallen wire
29. 29.⚠️ Is it safe to dry your hands first? (a) safe (b) not safe
30. 30.🔺 A current of 2.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
31. 31.🔢 To get a sensor reading onto a phone, which comes first: “the board reads it” or “the sensor measures”? (a) the sensor measures (b) the board reads it
32. 32.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
33. 33.📏 In the water-pipe picture of a circuit, resistance is like … (a) the flow of water (b) a bigger tank (c) a narrow pipe (d) the water pressure
34. 34.🗺️ In an input → process → output plan, is “the fan starts” the input, the process or the output? (a) input (b) output (c) process
35. 35.Which of these saves electricity? (a) close the fridge quickly (b) iron one shirt at a time (c) leave the TV on standby (d) leave fridge door open
36. 36.Which job is done by the reset button? (a) connect sensors and LEDs (b) keeps the voltage steady (c) brings power and code (d) restarts the program
37. 37.True or false: the voltmeter is joined across a part. (a) False (b) True
38. 38.🗺️ In an input → process → output plan, is “decide if soil is dry” the input, the process or the output? (a) output (b) process (c) input
39. 39.True or false: to fly a kite near wires is safe. (a) True (b) False
40. 40.🤖 Does a spinning top usually have a microcontroller inside? (a) Yes (b) No

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