Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 796 · 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 6 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
2. 2.🔺 A 20 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
3. 3.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) both parts (c) the else part (d) neither part
4. 4.🧩 Which part changes electrical energy into movement? (a) an LED (b) a fuse (c) a motor (d) a resistor
5. 5.📏 How many watts (W) is 1.7 kW?
6. 6.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
   The temperature is 24 °C. What is shown? (a) Hot (b) Warm (c) Cool
7. 7.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) changes the voltage (c) makes electricity (d) stores current
8. 8.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) in series (d) not joined
9. 9.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
10. 10.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 92 Ω resistor? (a) white-red-black (b) red-white-black (c) white-red-brown (d) brown-red-black
11. 11.📏 Voltmeter or ammeter: which one measures current? (a) ammeter (b) voltmeter
12. 12.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 410 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
13. 13.⚡ A 1.2 W device works on 12 V. What current does it take (in amperes)? =
14. 14.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a capacitor (c) a buzzer (d) a diode
15. 15.🔘 Two switches are in series. When does the bulb glow? (a) when both are ON (b) when both are OFF (c) when either is ON (d) never
16. 16.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) read the soil sensor (b) wait a few seconds (c) compare with the limit
17. 17.🔍 Which is the odd one out? (a) a woollen thread (b) an iron nail (c) aluminium foil (d) a metal paper clip
18. 18.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 30000 Ω resistor? (a) orange-black-red (b) orange-black-orange (c) yellow-orange-orange (d) orange-black-yellow
19. 19.🔘 Which kind of switch slides side to side? (a) a slide switch (b) a push button (c) a toggle switch (d) a tilt switch
20. 20.True or false: “the pump turns on” is the input. (a) False (b) True
21. 21.💡 In a series circuit, how many paths does the current have? (a) two (b) one for each bulb (c) none (d) one
22. 22.🔍 Which is the odd one out? (a) a rubber band (b) a ceramic cup (c) a steel spoon (d) a paper strip
23. 23.Which of these is measured in ohms (Ω)? (a) voltage (b) the push of a cell (c) resistance (d) energy used each second
24. 24.📶 Digital or analog: how bright a room is? (a) digital (b) analog
25. 25.💡 An LED is joined to a 5 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) does not light (b) lights up (c) may burn out
26. 26.True or false: voltage is measured in volts (V). (a) True (b) False
27. 27.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) cell (b) bulb (c) battery (d) ammeter
28. 28.⏱️ repeat 5 times { buzzer ON; wait 300 ms; buzzer OFF; wait 900 ms }
    How many milliseconds does this take in all?
29. 29.🔍 Which is the odd one out? (a) a glass marble (b) a metal paper clip (c) a rubber band (d) a rubber eraser
30. 30.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the metal tip (c) the bare end (d) the plastic handle
31. 31.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a woollen thread. Does the bulb glow? (a) No (b) Yes
32. 32.Which job needs a motor? (a) turn to an exact angle (b) beep an alarm (c) spin a robot’s wheels (d) open a gate to 90°
33. 33.Which of these has no microcontroller inside? (a) a microwave oven (b) a candle (c) a TV remote (d) a toy robot
34. 34.Which of these uses electricity? (a) a generator (b) a cell (c) a mobile phone (d) a wind turbine
35. 35.Which of these usually has a microcontroller inside? (a) a candle (b) a hand pump (c) a wind-up toy (d) a washing machine
36. 36.🔺 A current of 3 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
37. 37.True or false: to keep factory passwords is a risky habit. (a) True (b) False
38. 38.⚠️ Which power source should children use for electronics projects? (a) a small battery pack (b) a mains extension board (c) a wall socket (d) an inverter socket
39. 39.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 34 °C. What is shown? (a) Hot (b) Cool (c) Warm
40. 40.🔢 To plan an electronics project, which is the LAST step? (a) build it with an adult (b) test it and fix it (c) pick a problem to solve (d) list inputs and outputs

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