Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 76 · 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.Which of these mainly gives out light? (a) an electric iron (b) a doorbell (c) a table fan (d) a torch
2. 2.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = R ÷ I (c) V = I + R (d) V = I ÷ R
3. 3.Which job is done by the voltage regulator? (a) restarts the program (b) shows the board is on (c) connect sensors and LEDs (d) keeps the voltage steady
4. 4.🤖 if (light < 400) { lamp ON } else { lamp OFF }
   The light sensor reads 483. What happens? (a) lamp ON (b) lamp OFF
5. 5.True or false: resistance is measured in ohms (Ω). (a) True (b) False
6. 6.🔐 Is it a good or a risky habit to turn off unused gadgets? (a) risky habit (b) good habit
7. 7.True or false: to take cells out after use is safe. (a) False (b) True
8. 8.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) smaller (c) zero (d) stay the same
9. 9.🔁 x = 1
   repeat 3 times { x = x × 2 }
   What is x at the end?
10. 10.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
11. 11.🔺 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
12. 12.🔍 Which is the odd one out? (a) a push button (b) a motion sensor (c) a water pump (d) a turning knob
13. 13.🗺️ In an input → process → output plan, is “a temperature reading” the input, the process or the output? (a) output (b) process (c) input
14. 14.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) False (b) True
15. 15.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) No (b) Yes
16. 16.True or false: a tilt switch stays where you flip it. (a) True (b) False
17. 17.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 60 (c) 1000 (d) 100
18. 18.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 3 minutes?
19. 19.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is OFF, B is ON, C is ON and D is ON. Does the bulb glow? (a) Yes (b) No
20. 20.🔌 Why are electric wires covered in plastic? (a) plastic is an insulator (b) plastic makes current (c) plastic is a conductor (d) to make them heavy
21. 21.🔋 How many volts does one ordinary torch cell give? (a) 230 V (b) 15 V (c) 0.5 V (d) 1.5 V
22. 22.True or false: a thermistor senses how hot it is. (a) True (b) False
23. 23.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) never (b) only when both are OFF (c) only when both are ON (d) when either is ON
24. 24.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
25. 25.⚠️ Is it safe to fly a kite near wires? (a) not safe (b) safe
26. 26.🌈 A resistor has the colour bands grey, violet, yellow. What is its value in kilo-ohms (kΩ)? =
27. 27.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
28. 28.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
29. 29.📏 Which unit measures power? (a) ampere (A) (b) watt (W) (c) ohm (Ω) (d) volt (V)
30. 30.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
31. 31.🔢 To run one loop of a plant-watering program, which comes first: “wait a few seconds” or “switch the pump on/off”? (a) switch the pump on/off (b) wait a few seconds
32. 32.Which drawing is the symbol for a battery? (a) triangle, bar and arrows (b) many long-short pairs (c) a plain rectangle (d) a circle with A inside
33. 33.🤖 Does a bicycle bell usually have a microcontroller inside? (a) No (b) Yes
34. 34.🔺 A current of 0.25 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
35. 35.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
36. 36.🔁 repeat 4 times { repeat 6 times { beep } }
    How many beeps are there?
37. 37.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) half the voltage (c) the same voltage (d) no voltage
38. 38.🌈 Which band is read first on a resistor? (a) any band (b) the widest gap (c) the one nearest an end (d) the gold band
39. 39.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) a wire is cut (d) the loop is complete
40. 40.🌈 In the resistor colour code, which number does yellow stand for?

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