Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 359 · 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: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
2. 2.🔘 Which kind of switch closes when tipped over? (a) a push button (b) a reed switch (c) a slide switch (d) a tilt switch
3. 3.⚡ What does a siren mainly change electricity into? (a) heat (b) sound (c) light (d) movement
4. 4.Which of these mainly makes movement? (a) a traffic signal (b) a night lamp (c) an electric drill (d) an LED lamp
5. 5.Which of these is a conductor? (a) a rubber eraser (b) a rubber band (c) a plastic ruler (d) a graphite rod
6. 6.🔍 An object is 272 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
7. 7.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) large electric dial (d) low energy device
8. 8.🔍 Which is the odd one out? (a) a light level reading (b) count button presses (c) a soil moisture reading (d) a button press
9. 9.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 340 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
10. 10.🌐 Is a wind-up clock an IoT device? (a) not an IoT device (b) an IoT device
11. 11.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
12. 12.Which job is done by the power LED? (a) keeps the voltage steady (b) runs the program (c) restarts the program (d) shows the board is on
13. 13.True or false: a tilt switch springs back when let go. (a) True (b) False
14. 14.💡 3 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
15. 15.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = R ÷ I (c) V = I ÷ R (d) V = I × R
16. 16.📶 Digital or analog: how bright a room is? (a) digital (b) analog
17. 17.Which of these is an output? (a) a motion sensor (b) a sound sensor (c) a servo motor (d) a temperature sensor
18. 18.💡 4 identical bulbs are joined in parallel across a 3 V battery (ideal wires). How many volts does each bulb get? =
19. 19.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 10 (c) 1000 (d) 100
20. 20.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = V × I (d) R = I ÷ V
21. 21.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
22. 22.🤖 if (light < 400) { lamp ON } else { lamp OFF }
    The light sensor reads 383. What happens? (a) lamp OFF (b) lamp ON
23. 23.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a bulb (b) a long wire (c) a plug top (d) a fuse or MCB
24. 24.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 39 °C. What happens? (a) fan OFF (b) fan ON
25. 25.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they keep glowing (c) they get dimmer (d) they explode
26. 26.🌈 A resistor has the colour bands yellow, grey, yellow. What is its value in kilo-ohms (kΩ)? =
27. 27.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 370 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
28. 28.🔍 Which is the odd one out? (a) a copper wire (b) an iron nail (c) a graphite rod (d) a plastic ruler
29. 29.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
30. 30.🧮 A 1.2 V battery is joined to 2 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
31. 31.🔘 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 OFF, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
32. 32.🔁 count = 2
    while (count < 42) { count = count + 5 }
    How many times does the loop run?
33. 33.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) the colour of light (d) energy used each second
34. 34.📶 On a 5 V board, a pin set HIGH gives about … (a) 5 V (b) 0 V (c) 230 V (d) 50 V
35. 35.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
36. 36.Which of these is a risky habit? (a) keep factory passwords (b) install software updates (c) log out of shared phones (d) share only needed data
37. 37.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
38. 38.🔌 Is a dry cork a conductor or an insulator? (a) an insulator (b) a conductor
39. 39.🤖 if (temperature > 25) { fan ON } else { fan OFF }
    The temperature sensor reads 26 °C. What happens? (a) fan OFF (b) fan ON
40. 40.🌈 Which band is read first on a resistor? (a) the gold band (b) the widest gap (c) any band (d) the one nearest an end

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