Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 623 · 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.💡 An LED is joined to a 9 V battery through a 1000 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) may burn out (b) does not light (c) lights up
2. 2.🔍 Which is the odd one out? (a) throw cells in a fire (b) fly a kite near wires (c) poke things in a socket (d) stay away from pylons
3. 3.🔁 total = 0
   for i = 1 to 4 { total = total + i }
   What is total at the end?
4. 4.⚠️ Is it safe to touch a switch when wet? (a) safe (b) not safe
5. 5.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) stay the same (c) smaller (d) zero
6. 6.Which of these is the output? (a) a button press (b) an LED lights up (c) a motion sensor signal (d) count button presses
7. 7.Which job is done by the voltage regulator? (a) runs the program (b) keeps the voltage steady (c) connect sensors and LEDs (d) restarts the program
8. 8.Which of these is a conductor? (a) a paper strip (b) a wooden stick (c) a copper wire (d) a cotton thread
9. 9.True or false: two equal parallel lines is the symbol for a bulb. (a) False (b) True
10. 10.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
11. 11.📏 How many watts (W) is 1.7 kW?
12. 12.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
13. 13.🧩 A capacitor in a circuit can … (a) make light (b) spin a wheel (c) measure heat (d) store charge briefly
14. 14.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a wooden stick across the gap. Does the bulb glow? (a) Yes (b) No
15. 15.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 34 °C. What is shown? (a) Cool (b) Hot (c) Warm
16. 16.True or false: a transistor has coloured bands. (a) False (b) True
17. 17.Which drawing is the symbol for an LED? (a) a circle with V inside (b) a long and a short line (c) a circle with an X in it (d) triangle, bar and arrows
18. 18.What does a toggle switch do? (a) closes near a magnet (b) flips up or down (c) works only while pressed (d) springs back when let go
19. 19.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) wait a few seconds (b) compare with the limit (c) switch the pump on/off
20. 20.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) a power source (c) an input (d) an output
21. 21.🧮 Resistors of 47 Ω, 50 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
22. 22.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) Yes (b) No
23. 23.⚡ What does an LED lamp mainly change electricity into? (a) sound (b) movement (c) light (d) heat
24. 24.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “read the soil sensor”? (a) read the soil sensor (b) compare with the limit
25. 25.🔍 Which is the odd one out? (a) a soil moisture reading (b) a temperature reading (c) compare with a limit (d) a light level reading
26. 26.🔍 Which is the odd one out? (a) use a cable with cuts (b) fly kites in open fields (c) dry your hands first (d) build with an adult near
27. 27.Which of these is an output? (a) a temperature sensor (b) an LED (c) a keypad (d) a sound sensor
28. 28.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
29. 29.✏️ In a circuit diagram, which part is drawn as a circle with a cross? (a) LED (b) junction (c) battery (d) bulb
30. 30.⚠️ Why must we never touch switches with wet hands? (a) water makes it cold (b) it spoils the paint (c) water carries current (d) it is just untidy
31. 31.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave fridge door open (c) unplug idle chargers (d) leave the TV on standby
32. 32.What does the cloud server do? (a) reads values, decides (b) carries the data (c) stores data online (d) shows data to you
33. 33.✏️ In a circuit diagram, which part is drawn as a circle with M inside? (a) ammeter (b) battery (c) bulb (d) motor
34. 34.🗺️ In an input → process → output plan, is “an alert on the phone” the input, the process or the output? (a) input (b) process (c) output
35. 35.True or false: on a cell, “usually the red wire” means the + (positive) end. (a) False (b) True
36. 36.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
37. 37.What does a tilt switch do? (a) closes when tipped over (b) closes near a magnet (c) works only while pressed (d) stays where you flip it
38. 38.Which of these is an input? (a) a water pump (b) a sound sensor (c) a servo motor (d) a motor
39. 39.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
40. 40.Which of these is a risky habit? (a) set a strong password (b) accept every permission (c) read app permissions (d) install software updates

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