Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 416 · 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.Which of these is a good habit? (a) keep factory passwords (b) read app permissions (c) accept every permission (d) ignore update messages
2. 2.🔺 A current of 40 mA flows when 8.8 V is joined across a resistor. What is its resistance (in ohms)?
3. 3.⏱️ loop forever { LED ON; wait 900 ms; LED OFF; wait 150 ms }
   How many milliseconds does one blink (ON + OFF) take?
4. 4.🤖 When the main loop of a microcontroller program ends, what happens? (a) it stops forever (b) the board breaks (c) it deletes itself (d) it starts again
5. 5.Which of these is an insulator? (a) a dry cork (b) a safety pin (c) a graphite rod (d) a brass key
6. 6.True or false: a rubber band is an insulator. (a) False (b) True
7. 7.🌈 A resistor has the colour bands yellow, black, red. What is its value in kilo-ohms (kΩ)? =
8. 8.🔋 3 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)? =
9. 9.🔺 A current of 1.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
10. 10.🔌 Is a steel spoon a conductor or an insulator? (a) an insulator (b) a conductor
11. 11.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
12. 12.True or false: to use daylight to read saves electricity. (a) False (b) True
13. 13.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when both are OFF (c) when either is ON (d) when both are ON
14. 14.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
15. 15.Which drawing is the symbol for a diode? (a) a circle with M inside (b) a dot where wires meet (c) triangle against a bar (d) a straight line
16. 16.💡 5 identical bulbs are in parallel and each one takes 1 A. What total current (in amperes) comes from the battery? =
17. 17.⚡ What does an exhaust fan mainly change electricity into? (a) movement (b) heat (c) light (d) sound
18. 18.🔺 A current of 20 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
19. 19.🤖 if (temperature > 28) { fan ON } else { fan OFF }
    The temperature sensor reads 23 °C. What happens? (a) fan OFF (b) fan ON
20. 20.🔘 What does a switch do in a circuit? (a) makes electricity (b) changes the voltage (c) stores current (d) opens or closes the loop
21. 21.💡 3 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
22. 22.🔋 Identical cells side by side (in parallel) give … (a) no voltage (b) half the voltage (c) double the voltage (d) the same voltage
23. 23.💡 3 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
24. 24.🧮 A 3.5 V battery is joined to 5 Ω and 2 Ω resistors in series. What current flows (in amperes)? =
25. 25.🌈 In the resistor colour code, which number does red stand for?
26. 26.🔺 A current of 0.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
27. 27.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) pour water on them (b) shout for an adult (c) wait and watch (d) pull them by the hand
28. 28.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an input (c) an output (d) a fuse
29. 29.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
30. 30.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 25) { show “Warm” } else { show “Cool” }
    The temperature is 11 °C. What is shown? (a) Cool (b) Warm (c) Hot
31. 31.True or false: to switch off empty rooms saves electricity. (a) False (b) True
32. 32.True or false: to touch a switch when wet is not safe. (a) True (b) False
33. 33.🔋 What is a battery? (a) a switch with a lid (b) a kind of bulb (c) two or more cells joined (d) one single wire
34. 34.💡 In a series circuit, how many paths does the current have? (a) none (b) one (c) two (d) one for each bulb
35. 35.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
36. 36.True or false: a diode makes a beeping sound. (a) False (b) True
37. 37.⏱️ A program says “wait 2500 ms”. How many seconds is that? =
38. 38.📏 How many kilo-ohms (kΩ) is 1400 Ω? =
39. 39.🔍 Which is the odd one out? (a) a steel spoon (b) a brass key (c) a rubber eraser (d) a metal paper clip
40. 40.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same

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