Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 686 · 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.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) the sensor measures (b) the app shows it (c) the board reads it (d) the cloud stores it
2. 2.💡 5 identical bulbs are joined in series with a 5 V battery (ideal wires). How many volts does each bulb get? =
3. 3.🔢 To plan an electronics project, which is the FIRST step? (a) list inputs and outputs (b) draw the circuit diagram (c) pick a problem to solve (d) test it and fix it
4. 4.True or false: a circle with A inside is the symbol for an ammeter. (a) True (b) False
5. 5.Which of these has no microcontroller inside? (a) a wind-up toy (b) a washing machine (c) a smart watch (d) a microwave oven
6. 6.🔢 To run one loop of a plant-watering program, which comes first: “wait a few seconds” or “compare with the limit”? (a) compare with the limit (b) wait a few seconds
7. 7.🧩 Which component stores a little charge? (a) capacitor (b) thermistor (c) potentiometer (d) buzzer
8. 8.🔍 Which is the odd one out? (a) throw cells in a fire (b) poke things in a socket (c) climb an electric pole (d) fly kites in open fields
9. 9.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) use old filament bulbs (c) iron one shirt at a time (d) run fans in empty rooms
10. 10.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
11. 11.🔺 A 40 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
12. 12.Which of these usually has a microcontroller inside? (a) a bicycle bell (b) a wind-up toy (c) a washing machine (d) a hand pump
13. 13.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) adds 1 to count (d) prints 1
14. 14.🔋 Does a bicycle dynamo give electricity or use electricity? (a) gives electricity (b) uses electricity
15. 15.⚠️ Is it safe to keep drinks far away? (a) safe (b) not safe
16. 16.Which job needs a motor? (a) beep an alarm (b) show the temperature (c) move water to plants (d) spin a robot’s wheels
17. 17.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) compare with the limit (b) read the soil sensor (c) wait a few seconds
18. 18.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
19. 19.⏱️ A program says “wait 2750 ms”. How many seconds is that? =
20. 20.🔌 A gap of dry air between two wires acts as … (a) a switch that is ON (b) an insulator (c) a cell (d) a conductor
21. 21.💡 An LED is joined to a 3 V battery through a 220 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) does not light (b) lights up (c) may burn out
22. 22.🌈 A resistor has the colour bands red, green, black. What is its value (in ohms)?
23. 23.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) process (b) output (c) input
24. 24.⏱️ A program says “wait 8250 ms”. How many seconds is that? =
25. 25.What does a motor do? (a) blows if current is high (b) makes a beeping sound (c) limits the current (d) turns a fan or wheels
26. 26.🔋 How many 3 V cells must be joined in series to give 6 V?
27. 27.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 240 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
28. 28.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
29. 29.🔌 Is a metal paper clip a conductor or an insulator? (a) an insulator (b) a conductor
30. 30.💡 An LED is joined to a 3 V battery through a 330 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) does not light (c) lights up
31. 31.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
32. 32.💡 A battery lights 3 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
33. 33.True or false: an electric drill mainly makes movement. (a) False (b) True
34. 34.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
35. 35.🔋 Does a wind turbine give electricity or use electricity? (a) uses electricity (b) gives electricity
36. 36.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 260 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
37. 37.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) a series circuit (d) an open circuit
38. 38.🌈 A resistor has the colour bands orange, black, orange. What is its value (in ohms)?
39. 39.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
40. 40.🔦 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) No (b) Yes

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