Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 636 · 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.🧮 Resistors of 68 Ω, 100 Ω, 22 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
2. 2.True or false: to install software updates is a good habit. (a) True (b) False
3. 3.🔺 A current of 1.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
4. 4.⚠️ Is it safe to take cells out after use? (a) not safe (b) safe
5. 5.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) never (b) only when both are ON (c) only when both are OFF (d) when either is ON
6. 6.Which of these saves electricity? (a) use old filament bulbs (b) switch off empty rooms (c) leave the TV on standby (d) run fans in empty rooms
7. 7.🔺 A 9.4 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
8. 8.🔘 Which kind of switch works only while pressed? (a) a reed switch (b) a toggle switch (c) a slide switch (d) a push button
9. 9.🔁 What does a variable do in a program? (a) stores a value (b) blinks an LED (c) measures light (d) joins two wires
10. 10.🔍 A distance sensor sends a sound pulse and hears the echo 8 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
11. 11.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 5 % (c) 0 % (d) 50 %
12. 12.🔺 A current of 50 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
14. 14.🏠 Which is a smart-home example? (a) a hand fan (b) a printed map (c) a candle in a jar (d) lights on from an app
15. 15.⚡ What does a mixer grinder mainly change electricity into? (a) light (b) heat (c) movement (d) sound
16. 16.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
17. 17.🔘 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 ON, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
18. 18.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
19. 19.🔦 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
20. 20.🔋 How many 3 V cells must be joined in series to give 24 V?
21. 21.📶 On a 5 V board, a pin set HIGH gives about … (a) 5 V (b) 50 V (c) 0 V (d) 230 V
22. 22.Which of these is an IoT device? (a) a plain wall switch (b) a paper calendar (c) a Wi-Fi doorbell camera (d) a wind-up clock
23. 23.🔍 Which is the odd one out? (a) unplug idle chargers (b) set the AC to 24 °C (c) close the fridge quickly (d) iron one shirt at a time
24. 24.True or false: the voltmeter is joined across a part. (a) True (b) False
25. 25.🧩 Which component senses how hot it is? (a) transistor (b) resistor (c) fuse (d) thermistor
26. 26.Which drawing is the symbol for a voltmeter? (a) a small empty box (b) a plain rectangle (c) a circle with V inside (d) a circle with an X in it
27. 27.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
28. 28.🌈 In the resistor colour code, which number does blue stand for?
29. 29.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is ON (c) the bulb is unscrewed (d) a wire is cut
30. 30.Which of these is a conductor? (a) a ceramic cup (b) a dry cork (c) a copper wire (d) a plastic straw
31. 31.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
32. 32.True or false: resistance is measured in watts (W). (a) False (b) True
33. 33.🔍 Which is the odd one out? (a) a wooden stick (b) a graphite rod (c) a steel spoon (d) a brass key
34. 34.🔐 Privacy for a smart device means controlling … (a) how loud it beeps (b) its battery size (c) who can see your data (d) its colour
35. 35.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
36. 36.🔢 To run one loop of a plant-watering program, which comes first: “switch the pump on/off” or “read the soil sensor”? (a) read the soil sensor (b) switch the pump on/off
37. 37.True or false: on an LED, the longer leg is the anode (+). (a) True (b) False
38. 38.🔘 Which kind of switch closes when tipped over? (a) a toggle switch (b) a push button (c) a reed switch (d) a tilt switch
39. 39.True or false: the ammeter measures current. (a) False (b) True
40. 40.True or false: many long-short pairs is the symbol for a battery. (a) True (b) False

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