Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 977 · 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: “a door: open or shut” is a digital signal. (a) True (b) False
2. 2.Which of these is the process? (a) a motion sensor signal (b) count button presses (c) a buzzer beeps (d) a soil moisture reading
3. 3.📏 In the water-pipe picture of a circuit, current is like … (a) the flow of water (b) the pipe colour (c) the water pressure (d) a narrow pipe
4. 4.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) the board reads it (b) the cloud stores it (c) the sensor measures (d) it is sent by Wi-Fi
5. 5.True or false: aluminium foil is a conductor. (a) False (b) True
6. 6.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) wait a few seconds (b) compare with the limit (c) read the soil sensor (d) switch the pump on/off
7. 7.🌈 A resistor has the colour bands green, grey, orange. What is its value in kilo-ohms (kΩ)? =
8. 8.🔍 Which is the odd one out? (a) use daylight to read (b) unplug idle chargers (c) close the fridge quickly (d) use old filament bulbs
9. 9.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 volt (d) 1 ampere
10. 10.🔋 3 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)? =
11. 11.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
12. 12.💡 3 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?
13. 13.💡 A red LED uses 2 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
14. 14.🌈 A resistor has the colour bands orange, black, yellow. What is its value in kilo-ohms (kΩ)? =
15. 15.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
16. 16.🌐 In an IoT system, which part carries the data? (a) cloud server (b) sensor (c) microcontroller (d) Wi-Fi
17. 17.📏 How many kilo-ohms (kΩ) is 2800 Ω? =
18. 18.True or false: a buzzer smooths a wobbly supply. (a) False (b) True
19. 19.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
20. 20.True or false: to turn off unused gadgets is a good habit. (a) False (b) True
21. 21.🔍 Which is the odd one out? (a) open a phone charger (b) keep drinks far away (c) fly a kite near wires (d) poke things in a socket
22. 22.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 550 ms }
    How many milliseconds does one blink (ON + OFF) take?
23. 23.🔍 Which is the odd one out? (a) close the fridge quickly (b) iron one shirt at a time (c) use LED lamps (d) switch off empty rooms
24. 24.🔺 A current of 50 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
25. 25.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber band across the gap. Does the bulb glow? (a) Yes (b) No
26. 26.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) battery (b) wire (c) cell (d) resistor
27. 27.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 510 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
28. 28.🔍 Which is the odd one out? (a) a room heater (b) a rice cooker (c) a street light (d) an electric iron
29. 29.Which of these is the output? (a) a temperature reading (b) a buzzer beeps (c) a motion sensor signal (d) a button press
30. 30.🌐 A soil sensor sends a reading to an app every 15 minutes. How many readings arrive in 1 hour?
31. 31.⚡ What does a torch mainly change electricity into? (a) sound (b) movement (c) light (d) heat
32. 32.⚡ What does an electric kettle mainly change electricity into? (a) movement (b) heat (c) sound (d) light
33. 33.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
34. 34.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) voltmeter (b) cell (c) switch (d) LED
35. 35.⚡ Which tiny particles drift along a metal wire to carry the current? (a) electrons (b) photons (c) water drops (d) dust particles
36. 36.⚙️ Which actuator would you use to move water to plants? (a) a pump (b) a servo motor (c) a motor (d) a display
37. 37.True or false: a traffic signal mainly gives out heat. (a) True (b) False
38. 38.Which of these is true of a series circuit? (a) own switch for each bulb (b) one out, the rest glow (c) a single current path (d) many paths for current
39. 39.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
40. 40.🤖 if (temperature > 38) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 31 °C. What is shown? (a) Hot (b) Cool (c) Warm

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