Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 909 · 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 is measured in watts (W)? (a) power (b) voltage (c) the flow of charge (d) current
2. 2.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
3. 3.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
4. 4.Which of these is measured in amperes (A)? (a) power (b) the flow of charge (c) how much a part resists (d) energy used each second
5. 5.True or false: “a break stops every bulb” is true of a parallel circuit. (a) False (b) True
6. 6.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) neither part (c) the else part (d) both parts
7. 7.True or false: a thermistor senses how hot it is. (a) True (b) False
8. 8.🔁 count = 4
   while (count < 20) { count = count + 2 }
   How many times does the loop run?
9. 9.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity
10. 10.🔺 A current of 0.2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
11. 11.⚡ An 18 W device works on 9 V. What current does it take (in amperes)? =
12. 12.Which of these is the input? (a) a soil moisture reading (b) an LED lights up (c) an alert on the phone (d) the pump turns on
13. 13.🔺 A current of 50 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
14. 14.Which of these wastes electricity? (a) use LED lamps (b) leave the TV on standby (c) set the AC to 24 °C (d) use daylight to read
15. 15.True or false: to switch on lamps at dusk, use a light sensor. (a) False (b) True
16. 16.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
17. 17.🔌 Is a steel spoon a conductor or an insulator? (a) a conductor (b) an insulator
18. 18.🔘 A bulb and a cell are joined through 5 switches on 5 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
19. 19.Which job needs a sound sensor? (a) warn of a gas leak (b) keep an incubator warm (c) switch on with a clap (d) make a parking alarm
20. 20.⚡ A device works on 9 V and takes 0.25 A. What is its power (in watts)? =
21. 21.⚠️ Is it safe to climb an electric pole? (a) not safe (b) safe
22. 22.⚡ A fan changes electrical energy mainly into which kind of energy? (a) light energy (b) movement energy (c) sound energy (d) chemical energy
23. 23.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
24. 24.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
25. 25.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) symbols are heavier (c) to make it colourful (d) quick and clear for all
26. 26.🔁 count = 5
    repeat 2 times { count = count + 6 }
    What is count at the end?
27. 27.True or false: a line lifted at a gap is the symbol for a voltmeter. (a) False (b) True
28. 28.🌈 Which band is read first on a resistor? (a) the widest gap (b) the gold band (c) any band (d) the one nearest an end
29. 29.What does a fuse do? (a) turns a fan or wheels (b) limits the current (c) blows if current is high (d) beeps for an alarm
30. 30.📶 Digital or analog: HIGH or LOW only? (a) analog (b) digital
31. 31.🌐 In an IoT system, which part reads values, decides? (a) actuator (b) microcontroller (c) phone app (d) cloud server
32. 32.⚠️ Which power source should children use for electronics projects? (a) a mains extension board (b) an inverter socket (c) a wall socket (d) a small battery pack
33. 33.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) run fans in empty rooms (d) use daylight to read
34. 34.True or false: on an LED, the leg by the flat edge is the anode (+). (a) False (b) True
35. 35.💡 In a series circuit, how many paths does the current have? (a) one (b) one for each bulb (c) two (d) none
36. 36.True or false: a laptop has a built-in keyboard. (a) True (b) False
37. 37.📏 How many milliamperes (mA) make 1 ampere? (a) 100 (b) 10 (c) 60 (d) 1000
38. 38.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
39. 39.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
40. 40.🤖 Microcontroller or laptop: which one runs one small program? (a) microcontroller (b) laptop

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