Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 460 · 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 motor beeps for an alarm. (a) True (b) False
2. 2.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
3. 3.🧩 Which component blows if current is high? (a) fuse (b) thermistor (c) resistor (d) capacitor
4. 4.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) read the soil sensor (b) compare with the limit (c) wait a few seconds
5. 5.🔁 count = 1
   repeat 3 times { count = count + 3 }
   What is count at the end?
6. 6.🧩 Which component smooths a wobbly supply? (a) capacitor (b) fuse (c) LDR (d) buzzer
7. 7.Which of these uses electricity? (a) a solar panel (b) a cell (c) a bicycle dynamo (d) a refrigerator
8. 8.💡 4 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
9. 9.Which of these is true of a series circuit? (a) used in house wiring (b) one out, the rest glow (c) bulbs share the voltage (d) each gets the full volts
10. 10.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) set the AC to 24 °C (d) use old filament bulbs
11. 11.🔺 A current of 50 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
12. 12.True or false: a microcontroller uses very little power. (a) False (b) True
13. 13.🔘 Which kind of switch stays where you flip it? (a) a slide switch (b) a reed switch (c) a toggle switch (d) a push button
14. 14.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
15. 15.🔘 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 ON. Does the bulb glow? (a) No (b) Yes
16. 16.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) half the voltage (c) no voltage (d) the same voltage
17. 17.🔁 count = 5
    while (count < 29) { count = count + 4 }
    How many times does the loop run?
18. 18.🧩 Which component stores a little charge? (a) buzzer (b) LDR (c) capacitor (d) resistor
19. 19.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) each gets full voltage (c) so all go off together (d) to save copper only
20. 20.🔺 A current of 0.25 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
21. 21.⚡ A device works on 9 V and takes 0.25 A. What is its power (in watts)? =
22. 22.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
23. 23.🔐 Is it a good or a risky habit to keep factory passwords? (a) good habit (b) risky habit
24. 24.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 LOW
    set pin 8 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
25. 25.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
26. 26.True or false: current is measured in amperes (A). (a) True (b) False
27. 27.True or false: “a door: open or shut” is an analog signal. (a) True (b) False
28. 28.🔺 A current of 20 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
29. 29.🌈 A resistor has the colour bands brown, black, red. What is its value in kilo-ohms (kΩ)? =
30. 30.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) takes 1 away (d) sets count to 1
31. 31.True or false: a circle with M inside is the symbol for a motor. (a) True (b) False
32. 32.🔌 Is a glass marble a conductor or an insulator? (a) a conductor (b) an insulator
33. 33.🔋 Does a television give electricity or use electricity? (a) uses electricity (b) gives electricity
34. 34.🔘 Which kind of switch springs back when let go? (a) a reed switch (b) a toggle switch (c) a tilt switch (d) a push button
35. 35.🔺 A 6 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
36. 36.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 5 hours?
37. 37.🔍 Which is the odd one out? (a) a wind-up clock (b) an app-controlled bulb (c) a battery torch (d) a plain wall switch
38. 38.🌈 A resistor has the colour bands white, black, black. What is its value (in ohms)?
39. 39.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
40. 40.What does a resistor do? (a) has coloured bands (b) stores a little charge (c) makes things spin (d) turns a fan or wheels

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