Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 465 · 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 grey, white, red. What is its value in kilo-ohms (kΩ)? =
2. 2.📏 In the water-pipe picture of a circuit, current is like … (a) the water pressure (b) the pipe colour (c) a narrow pipe (d) the flow of water
3. 3.True or false: “one out, the rest glow” is true of a parallel circuit. (a) False (b) True
4. 4.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
   How many times does the LED blink in 4 seconds?
5. 5.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
6. 6.🔍 Which sensor would you use to switch on with a clap? (a) a sound sensor (b) a temperature sensor (c) a light sensor (d) a motion sensor
7. 7.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) process (b) output (c) input
8. 8.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
9. 9.💡 In a series circuit, how many paths does the current have? (a) one (b) two (c) none (d) one for each bulb
10. 10.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 40 readings take?
11. 11.True or false: a woollen thread is an insulator. (a) True (b) False
12. 12.⚙️ Which actuator would you use to show a status light? (a) a servo motor (b) a buzzer (c) a display (d) an LED
13. 13.🔘 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
14. 14.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) one out, the rest glow (c) bulbs share the voltage (d) a break stops every bulb
15. 15.True or false: an LDR senses how bright it is. (a) True (b) False
16. 16.💡 What does LED stand for? (a) light energy dial (b) large electric dial (c) low energy device (d) light-emitting diode
17. 17.🔐 Which is the strongest password for a home smart camera? (a) 123456 (b) Tiger#Lamp42!Moon (c) password (d) admin
18. 18.Which of these is a conductor? (a) an iron nail (b) a wooden stick (c) a dry cork (d) a paper strip
19. 19.🔋 Does a refrigerator give electricity or use electricity? (a) uses electricity (b) gives electricity
20. 20.What does a capacitor do? (a) boosts a small signal (b) limits the current (c) stores a little charge (d) makes a beeping sound
21. 21.🔺 A current of 1.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
22. 22.⚙️ Which actuator would you use to open a gate to 90°? (a) an LED (b) a servo motor (c) a pump (d) a buzzer
23. 23.🔌 Is a sound sensor an input or an output for a microcontroller? (a) input (b) output
24. 24.🌈 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
25. 25.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
26. 26.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) laptop (b) microcontroller
27. 27.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 watt (d) 1 kilowatt-hour (kWh)
28. 28.True or false: on a cell, “the flat end” means the + (positive) end. (a) True (b) False
29. 29.🔍 Which is the odd one out? (a) a metal paper clip (b) aluminium foil (c) a dry cork (d) a graphite rod
30. 30.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) True (b) False
31. 31.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity
32. 32.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
33. 33.True or false: “one bulb out, all go out” is true of a series circuit. (a) True (b) False
34. 34.🔁 What does a variable do in a program? (a) joins two wires (b) blinks an LED (c) measures light (d) stores a value
35. 35.⚡ A device works on 9 V and takes 3 A. What is its power (in watts)? =
36. 36.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
37. 37.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) one loose end (d) a plastic gap
38. 38.🧮 A 10 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
39. 39.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
40. 40.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids