Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 138 · 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.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
2. 2.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) in series (c) in parallel (d) not joined
3. 3.Which of these is an insulator? (a) a brass key (b) a safety pin (c) a wooden stick (d) a copper wire
4. 4.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) to make it colourful (c) to hide the circuit (d) symbols are heavier
5. 5.🧩 A capacitor in a circuit can … (a) make light (b) measure heat (c) store charge briefly (d) spin a wheel
6. 6.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
7. 7.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
8. 8.🌈 A resistor has the colour bands violet, green, red. What is its value in kilo-ohms (kΩ)? =
9. 9.🧮 A 0.8 V battery is joined to 4 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
10. 10.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 47. What happens? (a) red LED ON (b) green LED ON
11. 11.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) ammeter (b) battery (c) diode (d) cell
12. 12.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
13. 13.Which job is done by the pins? (a) connect sensors and LEDs (b) brings power and code (c) runs the program (d) keeps the voltage steady
14. 14.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
15. 15.⚡ 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
16. 16.Which of these is the input? (a) an alert on the phone (b) the pump turns on (c) compare with a limit (d) a light level reading
17. 17.🔌 Is a cotton thread a conductor or an insulator? (a) a conductor (b) an insulator
18. 18.True or false: on an LED, the longer leg is the anode (+). (a) True (b) False
19. 19.🧩 Which component makes a beeping sound? (a) fuse (b) LED (c) buzzer (d) LDR
20. 20.🏠 Which is a smart-home example? (a) a candle in a jar (b) a printed map (c) a hand fan (d) lights on from an app
21. 21.⏱️ repeat 8 times { buzzer ON; wait 600 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
22. 22.🔁 count = 4
    repeat 2 times { count = count + 10 }
    What is count at the end?
23. 23.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
24. 24.🌈 A resistor has the colour bands grey, orange, yellow. What is its value in kilo-ohms (kΩ)? =
25. 25.Which of these is a good habit? (a) share camera links (b) log out of shared phones (c) accept every permission (d) reuse one password
26. 26.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
27. 27.What does a fuse do? (a) turns a fan or wheels (b) senses how hot it is (c) makes things spin (d) blows if current is high
28. 28.⚙️ Which actuator would you use to open a gate to 90°? (a) a servo motor (b) a motor (c) a buzzer (d) a display
29. 29.🔌 Is a plastic straw a conductor or an insulator? (a) an insulator (b) a conductor
30. 30.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
31. 31.🔐 Is it a good or a risky habit to share the Wi-Fi key? (a) risky habit (b) good habit
32. 32.🔘 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 OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
33. 33.🧮 Five equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
34. 34.🔍 Which is the odd one out? (a) use mains for a project (b) poke things in a socket (c) throw cells in a fire (d) dry your hands first
35. 35.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 LOW
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
36. 36.Which of these is true of a parallel circuit? (a) a single current path (b) bulbs share the voltage (c) a break stops every bulb (d) used in house wiring
37. 37.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
38. 38.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) False (b) True
39. 39.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 100 (c) 60 (d) 1000
40. 40.⚡ What does a water heater mainly change electricity into? (a) light (b) movement (c) heat (d) sound

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