Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 272 · 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.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 3 glow? (a) No (b) Yes
2. 2.Which of these is not safe? (a) dry your hands first (b) touch a switch when wet (c) take cells out after use (d) use small battery cells
3. 3.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a full circuit (d) a series circuit
4. 4.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
5. 5.🌐 What does IoT stand for? (a) Internet of Things (b) Internet of Talk (c) Inside of Toys (d) Input of Tools
6. 6.🔘 When a switch is ON, the circuit is … (a) closed (b) open (c) cut (d) broken
7. 7.🔍 Which is the odd one out? (a) an electric toy car (b) a mixer grinder (c) an electric drill (d) an electric iron
8. 8.🔁 count = 9
   repeat 7 times { count = count + 7 }
   What is count at the end?
9. 9.🔺 A current of 25 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
10. 10.🔺 A current of 0.1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
11. 11.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) a wire has come loose (d) the bulb is unscrewed
12. 12.Which of these usually has a microcontroller inside? (a) a plain wall switch (b) a candle (c) a wind-up toy (d) a digital alarm clock
13. 13.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) False (b) True
14. 14.⚡ What does a street light mainly change electricity into? (a) light (b) movement (c) heat (d) sound
15. 15.🔋 How many 1.2 V cells must be joined in series to give 3.6 V?
16. 16.True or false: a wooden stick is a conductor. (a) True (b) False
17. 17.🔍 Which is the odd one out? (a) a rubber band (b) a safety pin (c) a plastic straw (d) a rubber eraser
18. 18.🔺 A 45 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
19. 19.🤖 How does a new program get onto a microcontroller board? (a) drawn with a pen (b) typed on the chip (c) uploaded over USB (d) sent by sound
20. 20.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
21. 21.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) none (c) one (d) two
22. 22.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
23. 23.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
24. 24.🔍 Which is the odd one out? (a) the pump turns on (b) an LED lights up (c) an alert on the phone (d) decide if soil is dry
25. 25.Which job needs a light sensor? (a) switch on with a clap (b) start a fan when hot (c) close a window in rain (d) switch on lamps at dusk
26. 26.💡 6 identical bulbs are in parallel and each one takes 1 A. What total current (in amperes) comes from the battery? =
27. 27.⚡ What does a night lamp mainly change electricity into? (a) sound (b) movement (c) heat (d) light
28. 28.True or false: “one out, the rest glow” is true of a parallel circuit. (a) False (b) True
29. 29.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
30. 30.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the USB port (b) the voltage regulator (c) the pins (d) the main chip
31. 31.🌐 Is a fitness band with app an IoT device? (a) not an IoT device (b) an IoT device
32. 32.🔁 x = 3
    repeat 4 times { x = x × 2 }
    What is x at the end?
33. 33.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
34. 34.💡 3 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
35. 35.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 630 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
36. 36.🔺 A current of 25 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
37. 37.🔍 Which sensor would you use to switch on with a clap? (a) a gas sensor (b) a temperature sensor (c) a sound sensor (d) a distance sensor
38. 38.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the gold band (c) the widest gap (d) any band
39. 39.🧩 A capacitor in a circuit can … (a) make light (b) spin a wheel (c) store charge briefly (d) measure heat
40. 40.True or false: “own switch for each bulb” is true of a parallel circuit. (a) False (b) True

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