Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 349 · 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.💡 6 identical bulbs are in parallel and each bulb has its own switch on its path. 3 of the switches are OFF and the rest are ON. How many bulbs glow?
2. 2.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an LED lamp (c) a candle (d) an oil lamp
3. 3.⚠️ Why must we never touch switches with wet hands? (a) it spoils the paint (b) it is just untidy (c) water makes it cold (d) water carries current
4. 4.⚠️ Is it safe to fly kites in open fields? (a) safe (b) not safe
5. 5.🔘 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) Yes (b) No
6. 6.🔍 Which is the odd one out? (a) a graphite rod (b) a copper wire (c) aluminium foil (d) a glass marble
7. 7.⚠️ Is it safe to touch a switch when wet? (a) safe (b) not safe
8. 8.🌈 A resistor has the colour bands brown, violet, yellow. What is its value in kilo-ohms (kΩ)? =
9. 9.True or false: to measure classroom noise, use a sound sensor. (a) True (b) False
10. 10.True or false: a toaster mainly makes sound. (a) True (b) False
11. 11.🔌 A gap of dry air between two wires acts as … (a) a switch that is ON (b) a cell (c) an insulator (d) a conductor
12. 12.🔍 Which is the odd one out? (a) a tube light (b) a ceiling fan (c) a torch (d) a traffic signal
13. 13.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 3.5 V supply. What current flows (in mA)?
14. 14.🌈 A resistor has the colour bands blue, green, red. What is its value (in ohms)?
15. 15.🧩 Which component makes a beeping sound? (a) motor (b) buzzer (c) LDR (d) diode
16. 16.🔋 Identical cells side by side (in parallel) give … (a) the same voltage (b) no voltage (c) double the voltage (d) half the voltage
17. 17.True or false: to stop a robot near walls, use a gas sensor. (a) True (b) False
18. 18.🔋 Cells joined + to − in a row (series) give … (a) a smaller voltage (b) a bigger voltage (c) the same voltage (d) no voltage
19. 19.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 4 hours?
20. 20.🧮 Two resistors in parallel give a total that is … (a) their sum (b) always zero (c) more than either one (d) less than either one
21. 21.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) junction (b) diode (c) resistor (d) switch
22. 22.Which of these is a conductor? (a) a paper strip (b) an iron nail (c) a woollen thread (d) a rubber band
23. 23.True or false: to accept every permission is a risky habit. (a) False (b) True
24. 24.🔺 A current of 20 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
25. 25.Which of these is not an IoT device? (a) a fitness band with app (b) a Wi-Fi doorbell camera (c) an app-controlled bulb (d) a battery torch
26. 26.True or false: a resistor makes a beeping sound. (a) True (b) False
27. 27.Which of these is true of a series circuit? (a) many paths for current (b) bulbs share the voltage (c) used in house wiring (d) one out, the rest glow
28. 28.⏱️ A program says “wait 2750 ms”. How many seconds is that? =
29. 29.🔌 Is a buzzer an input or an output for a microcontroller? (a) output (b) input
30. 30.🧩 Which component limits the current? (a) fuse (b) motor (c) capacitor (d) resistor
31. 31.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V × I (c) R = V + I (d) R = V ÷ I
32. 32.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 380 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
33. 33.True or false: a microcontroller has no screen of its own. (a) False (b) True
34. 34.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
35. 35.🔢 To plan an electronics project, which comes first: “list inputs and outputs” or “draw the circuit diagram”? (a) draw the circuit diagram (b) list inputs and outputs
36. 36.🔋 How many 1.5 V cells must be joined in series to give 4.5 V?
37. 37.True or false: to post your live location is a risky habit. (a) True (b) False
38. 38.True or false: on a cell, “usually the red wire” means the + (positive) end. (a) True (b) False
39. 39.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) test it and fix it (b) build it with an adult (c) pick a problem to solve (d) list inputs and outputs
40. 40.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 60 (c) 10 (d) 1000

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