Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 155 · 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 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
2. 2.Which job needs a soil moisture sensor? (a) switch on with a clap (b) measure classroom noise (c) spot someone walking in (d) water a dry plant
3. 3.🌐 How does a home IoT device usually send its data to the app? (a) by post (b) by shouting (c) through a candle (d) over Wi-Fi
4. 4.True or false: a washing machine usually has a microcontroller inside. (a) False (b) True
5. 5.🔍 Which is the odd one out? (a) aluminium foil (b) a woollen thread (c) a rubber band (d) a glass marble
6. 6.True or false: “own switch for each bulb” is true of a series circuit. (a) True (b) False
7. 7.⚠️ Is it safe to build with an adult near? (a) safe (b) not safe
8. 8.🔍 Which is the odd one out? (a) set a strong password (b) install software updates (c) change default passwords (d) ignore update messages
9. 9.Which drawing is the symbol for a battery? (a) a plain rectangle (b) a circle with an X in it (c) two or more cell symbols (d) a circle with a cross
10. 10.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 90 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
11. 11.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) all wires are joined (d) the bulb is unscrewed
12. 12.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) neither line (c) both lines (d) the longer line
13. 13.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
14. 14.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a short circuit (b) a parallel circuit (c) an open circuit (d) a safe circuit
15. 15.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) a break stops every bulb (c) one out, the rest glow (d) a single current path
16. 16.🔗 Series or parallel circuit: “one out, the rest glow”? (a) series (b) parallel
17. 17.⚡ What does a mixer grinder mainly change electricity into? (a) sound (b) heat (c) movement (d) light
18. 18.Which of these saves electricity? (a) iron one shirt at a time (b) use LED lamps (c) use old filament bulbs (d) run fans in empty rooms
19. 19.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 HIGH
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
20. 20.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 1 second?
21. 21.📶 Digital or analog: a button: pressed or not? (a) analog (b) digital
22. 22.🔍 Which is the odd one out? (a) accept every permission (b) ignore update messages (c) cover unused cameras (d) share camera links
23. 23.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 200 ms }
    How many milliseconds does one blink (ON + OFF) take?
24. 24.🗺️ In an input → process → output plan, is “a button press” the input, the process or the output? (a) output (b) process (c) input
25. 25.🔍 A distance sensor sends a sound pulse and hears the echo 10 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
26. 26.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
27. 27.🔍 Which is the odd one out? (a) use daylight to read (b) close the fridge quickly (c) unplug idle chargers (d) leave fridge door open
28. 28.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) bulb (b) wire (c) switch (d) resistor
29. 29.🔍 Which is the odd one out? (a) poke things in a socket (b) use a cable with cuts (c) touch a fallen wire (d) use small battery cells
30. 30.✏️ In a circuit diagram, which part is drawn as a straight line? (a) battery (b) voltmeter (c) junction (d) wire
31. 31.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
32. 32.📏 How many milliamperes (mA) is 1.99 A?
33. 33.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) ammeter (b) battery (c) capacitor (d) switch
34. 34.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
35. 35.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) wavy lines (c) straight lines (d) little stars
36. 36.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
37. 37.📏 Which unit measures the push of a cell? (a) ampere (A) (b) volt (V) (c) ohm (Ω) (d) watt (W)
38. 38.True or false: “one out, the rest glow” is true of a series circuit. (a) True (b) False
39. 39.Which of these is safe? (a) use a cable with cuts (b) stay away from pylons (c) open a phone charger (d) touch a fallen wire
40. 40.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) only when both are OFF (c) never (d) only when both are ON

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