Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 244 · 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.🤖 if (light < 400) { lamp ON } else { lamp OFF }
   The light sensor reads 451. What happens? (a) lamp ON (b) lamp OFF
2. 2.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
3. 3.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) input (b) output (c) process
4. 4.📏 How many watts (W) is 1.1 kW?
5. 5.Which of these means the circuit is open? (a) a wire is cut (b) all wires are joined (c) the loop is complete (d) the switch is ON
6. 6.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 1000 (b) 10 (c) 1024 (d) 100
7. 7.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a series circuit (d) a closed circuit
8. 8.⚡ What does a loudspeaker mainly change electricity into? (a) light (b) movement (c) heat (d) sound
9. 9.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = I ÷ V (c) R = V + I (d) R = V ÷ I
10. 10.True or false: to switch on lamps at dusk, use a gas sensor. (a) False (b) True
11. 11.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 700 ms }
    How many times does the LED blink in 2 seconds?
12. 12.Which of these is an insulator? (a) a paper strip (b) a steel spoon (c) a steel coin (d) a metal paper clip
13. 13.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
14. 14.🔍 Which is the odd one out? (a) a brass key (b) a metal paper clip (c) a copper wire (d) a ceramic cup
15. 15.True or false: to cover unused cameras is a risky habit. (a) False (b) True
16. 16.🔍 Which is the odd one out? (a) ignore update messages (b) install software updates (c) post your live location (d) share the Wi-Fi key
17. 17.💡 A red LED uses 2 V and should get 25 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
18. 18.True or false: the voltmeter is joined across a part. (a) False (b) True
19. 19.🔺 A 15 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
20. 20.True or false: a microcontroller runs many apps at once. (a) True (b) False
21. 21.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “wait a few seconds”? (a) read the soil sensor (b) wait a few seconds
22. 22.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
23. 23.🧮 A 10 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
24. 24.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) process (b) output (c) input
25. 25.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the process (c) the battery (d) the output
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 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) Yes (b) No
28. 28.True or false: a buzzer stores a little charge. (a) False (b) True
29. 29.🔐 Is it a good or a risky habit to share camera links? (a) risky habit (b) good habit
30. 30.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) the same voltage (c) no voltage (d) half the voltage
31. 31.🧮 A 100 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
32. 32.🔋 How many 1.5 V cells must be joined in series to give 6 V?
33. 33.🔺 A current of 1.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
34. 34.🤖 “if (A AND B)” is true when … (a) both are false (b) both A and B are true (c) only B is true (d) only A is true
35. 35.🧩 Which component glows using little power? (a) fuse (b) LDR (c) potentiometer (d) LED
36. 36.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 20 readings take?
37. 37.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 17 °C. What is shown? (a) Hot (b) Warm (c) Cool
38. 38.🔍 Which is the odd one out? (a) leave fridge door open (b) run fans in empty rooms (c) leave the TV on standby (d) use LED lamps
39. 39.📏 How many milliamperes (mA) make 1 ampere? (a) 100 (b) 1000 (c) 60 (d) 10
40. 40.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) laptop (b) microcontroller

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