Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 635 · 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 68 Ω resistor is joined in series with two equal 50 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
2. 2.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) to save copper only (c) each gets full voltage (d) so all go off together
3. 3.💡 4 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
4. 4.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
5. 5.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in parallel (c) by Wi-Fi (d) in series
6. 6.⏱️ A program says “wait 1500 ms”. How many seconds is that? =
7. 7.🔍 Which is the odd one out? (a) a battery torch (b) a wind-up clock (c) a Wi-Fi weather station (d) a pencil sharpener
8. 8.Which of these is an IoT device? (a) a wind-up clock (b) a pencil sharpener (c) a fitness band with app (d) a battery torch
9. 9.🔺 A 5 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
10. 10.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) quick and clear for all (d) symbols are heavier
11. 11.Which of these is measured in volts (V)? (a) the push of a cell (b) power (c) the flow of charge (d) resistance
12. 12.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 10 (c) 60 (d) 100
13. 13.⚠️ Is it safe to open a phone charger? (a) not safe (b) safe
14. 14.True or false: “many paths for current” is true of a parallel circuit. (a) False (b) True
15. 15.True or false: to open blinds at sunrise, use a light sensor. (a) False (b) True
16. 16.🌐 A weather station sends one reading every 20 seconds. How many readings does it send in 5 minutes?
17. 17.Which of these mainly gives out heat? (a) a doorbell (b) a loudspeaker (c) a room heater (d) a night lamp
18. 18.🔘 What does a switch do in a circuit? (a) changes the voltage (b) makes electricity (c) opens or closes the loop (d) stores current
19. 19.True or false: one tall, one short bar is the symbol for a switch. (a) False (b) True
20. 20.🔁 What does a variable do in a program? (a) measures light (b) stores a value (c) joins two wires (d) blinks an LED
21. 21.🔋 Does a battery give electricity or use electricity? (a) uses electricity (b) gives electricity
22. 22.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) neither part (d) the if part
23. 23.🧩 Which component boosts a small signal? (a) buzzer (b) transistor (c) diode (d) LED
24. 24.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I × R (c) V = I ÷ R (d) V = I + R
25. 25.🌈 A resistor has the colour bands orange, brown, red. What is its value in kilo-ohms (kΩ)? =
26. 26.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
27. 27.Which drawing is the symbol for a resistor? (a) a line lifted at a gap (b) a circle with a cross (c) a plain rectangle (d) a straight line
28. 28.Which of these mainly gives out light? (a) a water heater (b) an electric kettle (c) a traffic signal (d) a siren
29. 29.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
30. 30.Which of these wastes electricity? (a) switch off empty rooms (b) use LED lamps (c) use daylight to read (d) iron one shirt at a time
31. 31.🔦 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 plastic ruler. Does the bulb glow? (a) No (b) Yes
32. 32.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
33. 33.🔍 Which is the odd one out? (a) reuse one password (b) set up with a parent (c) turn off unused gadgets (d) change default passwords
34. 34.🧩 Which component smooths a wobbly supply? (a) buzzer (b) transistor (c) diode (d) capacitor
35. 35.🔢 To run one loop of a plant-watering program, which comes first: “switch the pump on/off” or “read the soil sensor”? (a) switch the pump on/off (b) read the soil sensor
36. 36.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 3100 Ω resistor? (a) orange-brown-red (b) orange-brown-orange (c) brown-orange-red (d) orange-brown-brown
37. 37.🔺 A current of 25 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
38. 38.⚡ Power tells us … (a) the length of a wire (b) the colour of light (c) energy used each second (d) the size of a cell
39. 39.🔐 Is it a good or a risky habit to log out of shared phones? (a) good habit (b) risky habit
40. 40.🌐 What does IoT stand for? (a) Inside of Toys (b) Internet of Things (c) Internet of Talk (d) Input of Tools

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