Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 273 · 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 circle with a cross is the symbol for a bulb. (a) True (b) False
2. 2.🧩 Which part changes electrical energy into movement? (a) an LED (b) a motor (c) a fuse (d) a resistor
3. 3.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the colour of light (d) the size of a cell
4. 4.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
5. 5.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
6. 6.Which job needs a motion sensor? (a) make a parking alarm (b) stop a robot near walls (c) water a dry plant (d) spot someone walking in
7. 7.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
8. 8.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
9. 9.🧮 Four equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
10. 10.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is ON, C is ON and D is ON. Does the bulb glow? (a) Yes (b) No
11. 11.🔺 A current of 0.1 A flows when 0.4 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.Which of these is a conductor? (a) a ceramic cup (b) a rubber band (c) a safety pin (d) a rubber eraser
13. 13.🌈 A resistor has the colour bands yellow, red, red. What is its value (in ohms)?
14. 14.🔢 To get a sensor reading onto a phone, what comes right after “the sensor measures”? (a) the app shows it (b) the cloud stores it (c) it is sent by Wi-Fi (d) the board reads it
15. 15.Which of these is measured in volts (V)? (a) resistance (b) current (c) the push of a cell (d) energy used each second
16. 16.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
17. 17.🔍 Which is the odd one out? (a) read app permissions (b) share only needed data (c) change default passwords (d) share camera links
18. 18.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) a wire has come loose (d) the bulb is unscrewed
19. 19.True or false: a bicycle bell usually has a microcontroller inside. (a) True (b) False
20. 20.🔍 Which is the odd one out? (a) a soil moisture reading (b) an alert on the phone (c) an LED lights up (d) a buzzer beeps
21. 21.🔺 A 3 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
22. 22.What does a toggle switch do? (a) works only while pressed (b) springs back when let go (c) closes near a magnet (d) stays where you flip it
23. 23.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
24. 24.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
25. 25.True or false: the ammeter measures current. (a) True (b) False
26. 26.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
27. 27.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
28. 28.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) motor (b) voltmeter (c) diode (d) LED
29. 29.💡 A red LED uses 2 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
30. 30.🔦 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
31. 31.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to store charge (c) to change its colour (d) to limit the current
32. 32.Which of these is a conductor? (a) a wooden stick (b) a copper wire (c) a dry cork (d) a paper strip
33. 33.🧮 A 22 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)?
34. 34.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
35. 35.🔋 What should you do with used-up cells? (a) bury them in soil (b) throw them in a fire (c) cut them open (d) give them for recycling
36. 36.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) takes 1 away (d) sets count to 1
37. 37.🔋 6 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
38. 38.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 60 (d) 10
39. 39.True or false: a small empty box is the symbol for a resistor. (a) True (b) False
40. 40.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water pressure (b) the pipe colour (c) the water tank lid (d) the tap handle

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