Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 448 · 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.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
2. 2.True or false: “a break stops every bulb” is true of a parallel circuit. (a) False (b) True
3. 3.🔺 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
4. 4.🧮 Five equal 500 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
5. 5.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) a Wi-Fi weather station (c) a fitness band with app (d) a wind-up clock
6. 6.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
7. 7.True or false: a dot where wires meet is the symbol for a wire. (a) True (b) False
8. 8.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
9. 9.What does the actuator do? (a) measures the real world (b) carries the data (c) stores data online (d) acts on a command
10. 10.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
11. 11.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
12. 12.🔋 Identical cells side by side (in parallel) give … (a) half the voltage (b) double the voltage (c) the same voltage (d) no voltage
13. 13.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 850 Ω resistor? (a) grey-green-red (b) green-grey-brown (c) grey-green-black (d) grey-green-brown
14. 14.Which of these has no microcontroller inside? (a) a digital thermometer (b) a microwave oven (c) a wind-up toy (d) a digital alarm clock
15. 15.🔌 Is a rubber band a conductor or an insulator? (a) a conductor (b) an insulator
16. 16.Which drawing is the symbol for a switch? (a) a line lifted at a gap (b) a circle with a cross (c) a circle with V inside (d) a circle with M inside
17. 17.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a plastic gap (d) a broken path
18. 18.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a cell is taken out
19. 19.True or false: to open blinds at sunrise, use a soil moisture sensor. (a) True (b) False
20. 20.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) stores a value (d) blinks an LED
21. 21.True or false: a microcontroller has no screen of its own. (a) False (b) True
22. 22.🔺 A current of 0.25 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🔐 Is it a good or a risky habit to change default passwords? (a) risky habit (b) good habit
24. 24.True or false: a plastic ruler is a conductor. (a) True (b) False
25. 25.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
26. 26.🧮 A 1.2 V battery is joined to 4 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
27. 27.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) two (c) none (d) one
28. 28.⏱️ How many milliseconds is a wait of 4.3 seconds?
29. 29.🔋 Does a power station give electricity or use electricity? (a) uses electricity (b) gives electricity
30. 30.💡 5 identical bulbs are in parallel and each bulb has its own switch on its path. 2 of the switches are OFF and the rest are ON. How many bulbs glow?
31. 31.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) compare with the limit (b) wait a few seconds (c) read the soil sensor
32. 32.🧮 A 1.3 V battery is joined to 3 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
33. 33.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the battery (c) the input (d) the process
34. 34.What does the microcontroller do? (a) stores data online (b) acts on a command (c) reads values, decides (d) carries the data
35. 35.⚠️ Is it safe to throw cells in a fire? (a) safe (b) not safe
36. 36.🧭 Which part of a microcontroller board restarts the program? (a) the USB port (b) the voltage regulator (c) the power LED (d) the reset button
37. 37.💡 2 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
38. 38.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) when both are ON (c) when either is ON (d) never
39. 39.🔺 A current of 20 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
40. 40.Which of these is measured in watts (W)? (a) the flow of charge (b) power (c) how much a part resists (d) voltage

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