Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 852 · 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: to take cells out after use is safe. (a) True (b) False
2. 2.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) True (b) False
3. 3.Which of these usually has a microcontroller inside? (a) a hand pump (b) a bicycle bell (c) a digital thermometer (d) a spinning top
4. 4.🔢 To plan an electronics project, what comes right after “list inputs and outputs”? (a) draw the circuit diagram (b) pick a problem to solve (c) test it and fix it (d) build it with an adult
5. 5.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) zero (c) smaller (d) bigger
6. 6.📏 How many kilowatts (kW) is 1450 W? =
7. 7.🔗 Series or parallel circuit: “one out, the rest glow”? (a) series (b) parallel
8. 8.🔺 A current of 1 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
9. 9.🤖 if (temperature > 25) { fan ON } else { fan OFF }
   The temperature sensor reads 17 °C. What happens? (a) fan ON (b) fan OFF
10. 10.Which of these gives us electricity? (a) a television (b) a water pump (c) an air conditioner (d) a cell
11. 11.🌈 A resistor has the colour bands green, yellow, orange. What is its value in kilo-ohms (kΩ)? =
12. 12.🔍 Which is the odd one out? (a) use old filament bulbs (b) switch off empty rooms (c) leave the TV on standby (d) run fans in empty rooms
13. 13.What does a slide switch do? (a) works only while pressed (b) closes near a magnet (c) flips up or down (d) slides side to side
14. 14.📶 Digital or analog: how bright a room is? (a) analog (b) digital
15. 15.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 5 % (c) 0 % (d) 50 %
16. 16.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 kilowatt-hour (kWh) (d) 1 ampere
17. 17.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
18. 18.True or false: the flow of charge is measured in volts (V). (a) True (b) False
19. 19.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I ÷ R (c) V = R ÷ I (d) V = I + R
20. 20.⚙️ What is an actuator? (a) a sensor (b) a program (c) a battery (d) an output that acts
21. 21.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
22. 22.🌐 A weather station sends one reading every 15 seconds. How many readings does it send in 9 minutes?
23. 23.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a woollen thread. Does the bulb glow? (a) No (b) Yes
24. 24.True or false: a long and a short line is the symbol for a cell. (a) True (b) False
25. 25.True or false: to change default passwords is a good habit. (a) True (b) False
26. 26.🔍 Which is the odd one out? (a) a pencil sharpener (b) a wind-up clock (c) a paper calendar (d) an app-controlled bulb
27. 27.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 10 (c) 60 (d) 100
28. 28.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
29. 29.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) No (b) Yes
30. 30.🔍 Which is the odd one out? (a) unplug idle chargers (b) use LED lamps (c) use daylight to read (d) leave the TV on standby
31. 31.True or false: “used in house wiring” is true of a parallel circuit. (a) False (b) True
32. 32.🔦 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 band. Does the bulb glow? (a) Yes (b) No
33. 33.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it changes colour (c) it makes a sound (d) it does not light
34. 34.📶 On a 5 V board, a pin set HIGH gives about … (a) 0 V (b) 5 V (c) 230 V (d) 50 V
35. 35.🔺 A current of 40 mA flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.Which of these is a good habit? (a) post your live location (b) cover unused cameras (c) keep factory passwords (d) share the Wi-Fi key
37. 37.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
38. 38.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
39. 39.🔺 A current of 10 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
40. 40.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the else part (c) the if part (d) both parts

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