Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 593 · 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.🔌 Is a light sensor an input or an output for a microcontroller? (a) output (b) input
2. 2.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) capacitor (b) wire (c) cell (d) bulb
3. 3.What does a potentiometer do? (a) boosts a small signal (b) smooths a wobbly supply (c) senses how hot it is (d) is a resistance knob
4. 4.True or false: energy used each second is measured in watts (W). (a) False (b) True
5. 5.True or false: “used in house wiring” is true of a series circuit. (a) True (b) False
6. 6.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) bigger (d) zero
7. 7.Which of these is an insulator? (a) a safety pin (b) an iron nail (c) a cotton thread (d) a steel spoon
8. 8.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 310 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
9. 9.Which of these mainly gives out light? (a) a ceiling fan (b) a table fan (c) a tube light (d) a mixer grinder
10. 10.True or false: a slide switch closes near a magnet. (a) False (b) True
11. 11.What does a resistor do? (a) stores a little charge (b) lets current go one way (c) blows if current is high (d) has coloured bands
12. 12.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a small battery pack (c) a mains extension board (d) a wall socket
13. 13.⚡ A device works on 1.5 V and takes 0.5 A. What is its power (in watts)? =
14. 14.🔋 A 12 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
15. 15.⚡ A 2.5 W device works on 5 V. What current does it take (in amperes)? =
16. 16.True or false: a circle with a cross is the symbol for a bulb. (a) True (b) False
17. 17.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) Yes (b) No
18. 18.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) pauses for half a second (c) turns the LED off (d) blinks 500 times
19. 19.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) a fuse (c) an output (d) an input
20. 20.🔺 A current of 1 A flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
21. 21.🤖 if (sound > 70) { red LED ON } else { green LED ON }
    The sound sensor reads 80. What happens? (a) red LED ON (b) green LED ON
22. 22.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
23. 23.🧮 A 7 V battery is joined to 4 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
24. 24.True or false: a circle with V inside is the symbol for a battery. (a) True (b) False
25. 25.💡 6 identical bulbs are in parallel and each one takes 1 A. What total current (in amperes) comes from the battery? =
26. 26.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I + R (c) V = I ÷ R (d) V = R ÷ I
27. 27.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 3 minutes?
28. 28.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
29. 29.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 1000 (c) 100 (d) 60
30. 30.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a buzzer (c) a resistor (d) a diode
31. 31.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
32. 32.💡 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) lights up (b) does not light (c) may burn out
33. 33.🔌 Is a motor an input or an output for a microcontroller? (a) input (b) output
34. 34.⚡ A 48 W device works on 24 V. What current does it take (in amperes)? =
35. 35.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) one loose end (d) a plastic gap
36. 36.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 607. What happens? (a) lamp ON (b) lamp OFF
37. 37.Which job needs a motion sensor? (a) keep an incubator warm (b) start a fan when hot (c) close a window in rain (d) spot someone walking in
38. 38.🔍 Which is the odd one out? (a) a paper calendar (b) a plain wall switch (c) a Wi-Fi doorbell camera (d) a pencil sharpener
39. 39.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. Does bulb 4 glow? (a) Yes (b) No
40. 40.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the longer line (c) both lines (d) the shorter line

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