Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 633 · 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.🧮 Three equal 150 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
2. 2.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) to save copper only (c) so all go off together (d) each gets full voltage
3. 3.🔋 4 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
4. 4.Which of these is the input? (a) an alert on the phone (b) decide if soil is dry (c) compare with a limit (d) a temperature reading
5. 5.Which of these is true of a series circuit? (a) each gets the full volts (b) used in house wiring (c) a single current path (d) own switch for each bulb
6. 6.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
7. 7.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
8. 8.🔺 A 0.8 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
9. 9.📏 Which unit measures resistance? (a) volt (V) (b) ampere (A) (c) watt (W) (d) ohm (Ω)
10. 10.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is OFF, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
11. 11.🔺 An 8 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
12. 12.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V × R (c) I = R ÷ V (d) I = V ÷ R
13. 13.🔍 Which is the odd one out? (a) turn off unused gadgets (b) post your live location (c) tap unknown app links (d) share camera links
14. 14.🌈 A resistor has the colour bands white, red, orange. What is its value in kilo-ohms (kΩ)? =
15. 15.True or false: triangle against a bar is the symbol for a switch. (a) False (b) True
16. 16.🔺 A 1 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
17. 17.🌐 In an IoT system, which part measures the real world? (a) cloud server (b) sensor (c) phone app (d) actuator
18. 18.🔺 A 0.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
19. 19.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
20. 20.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
21. 21.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
22. 22.🔐 Is it a good or a risky habit to share camera links? (a) good habit (b) risky habit
23. 23.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) a smaller voltage (c) the same voltage (d) a bigger voltage
24. 24.🌐 What does IoT stand for? (a) Inside of Toys (b) Internet of Things (c) Internet of Talk (d) Input of Tools
25. 25.True or false: on an LED, the shorter leg is the cathode (−). (a) True (b) False
26. 26.Which of these usually has a microcontroller inside? (a) a hand pump (b) a microwave oven (c) a candle (d) a spinning top
27. 27.Which drawing is the symbol for a switch? (a) one tall, one short bar (b) a small empty box (c) a line lifted at a gap (d) a straight line
28. 28.🔘 When a switch is ON, the circuit is … (a) open (b) broken (c) cut (d) closed
29. 29.📏 Which unit measures current? (a) ohm (Ω) (b) volt (V) (c) ampere (A) (d) watt (W)
30. 30.🔺 A current of 1 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
31. 31.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) unplug idle chargers (d) iron one shirt at a time
32. 32.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
33. 33.🔌 Is a wooden stick a conductor or an insulator? (a) an insulator (b) a conductor
34. 34.🌈 A resistor has the colour bands grey, brown, red. What is its value in kilo-ohms (kΩ)? =
35. 35.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) sound energy (b) light energy (c) chemical energy (d) movement energy
36. 36.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
37. 37.⏱️ A program says “wait 9250 ms”. How many seconds is that? =
38. 38.What does a reed switch do? (a) closes when tipped over (b) closes near a magnet (c) works only while pressed (d) slides side to side
39. 39.⏱️ repeat 3 times { buzzer ON; wait 900 ms; buzzer OFF; wait 300 ms }
    How many milliseconds does this take in all?
40. 40.⏱️ How many milliseconds is a wait of 4.5 seconds?

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