Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 629 · 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.🌈 A resistor has the colour bands orange, violet, red. What is its value (in ohms)?
2. 2.⚡ What does an LED lamp mainly change electricity into? (a) heat (b) sound (c) light (d) movement
3. 3.⚡ What does a tube light mainly change electricity into? (a) light (b) movement (c) heat (d) sound
4. 4.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) waits 500 seconds (c) pauses for half a second (d) turns the LED off
5. 5.💡 2 identical bulbs are joined in series with a 2 V battery (ideal wires). How many volts does each bulb get? =
6. 6.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 100 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
7. 7.⚠️ Which power source should children use for electronics projects? (a) a wall socket (b) an inverter socket (c) a mains extension board (d) a small battery pack
8. 8.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
9. 9.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) straight lines (c) wavy lines (d) dotted circles
10. 10.🌈 A resistor has the colour bands orange, red, red. What is its value (in ohms)?
11. 11.Which drawing is the symbol for a diode? (a) a circle with M inside (b) a circle with V inside (c) one tall, one short bar (d) triangle against a bar
12. 12.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
13. 13.True or false: a copper wire is a conductor. (a) True (b) False
14. 14.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
15. 15.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a safe circuit (b) a parallel circuit (c) an open circuit (d) a short circuit
16. 16.🔺 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
17. 17.🌈 Which band is read first on a resistor? (a) the widest gap (b) the one nearest an end (c) any band (d) the gold band
18. 18.Which of these is measured in watts (W)? (a) how much a part resists (b) the push of a cell (c) power (d) voltage
19. 19.🔋 5 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
20. 20.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
21. 21.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a rubber eraser. Does the bulb glow? (a) Yes (b) No
22. 22.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is OFF (d) a wire is cut
23. 23.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
24. 24.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
25. 25.⏱️ A program says “wait 7500 ms”. How many seconds is that? =
26. 26.Which of these mainly gives out light? (a) a mixer grinder (b) a night lamp (c) a loudspeaker (d) an electric iron
27. 27.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
28. 28.🧩 Which component boosts a small signal? (a) LDR (b) transistor (c) resistor (d) motor
29. 29.🔍 Which is the odd one out? (a) a doorbell (b) a night lamp (c) a siren (d) a loudspeaker
30. 30.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the sensor measures (b) it is sent by Wi-Fi (c) the cloud stores it (d) the app shows it
31. 31.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) compare with the limit (b) switch the pump on/off (c) wait a few seconds (d) read the soil sensor
32. 32.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) tell it your passwords (b) put it in the bathroom (c) mute it when not in use (d) let strangers use it
33. 33.Which job needs a display? (a) spin a robot’s wheels (b) beep an alarm (c) open a gate to 90° (d) show the temperature
34. 34.Which of these is true of a series circuit? (a) each gets the full volts (b) own switch for each bulb (c) bulbs share the voltage (d) used in house wiring
35. 35.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to store charge (c) to make it brighter (d) to change its colour
36. 36.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) both are false (c) only A is true (d) only B is true
37. 37.True or false: to stop if a part gets hot is not safe. (a) True (b) False
38. 38.🧮 Two resistors in parallel give a total that is … (a) their sum (b) less than either one (c) more than either one (d) always zero
39. 39.🤖 Microcontroller or laptop: which one runs one small program? (a) laptop (b) microcontroller
40. 40.⚠️ Is it safe to stop if a part gets hot? (a) not safe (b) safe

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