Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 991 · 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 is the odd one out? (a) an LED (b) a sound sensor (c) a motion sensor (d) a temperature sensor
2. 2.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the process (c) the battery (d) the output
3. 3.🔌 Is an iron nail a conductor or an insulator? (a) a conductor (b) an insulator
4. 4.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
5. 5.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an output (c) an input (d) a fuse
6. 6.⚠️ Is it safe to use small battery cells? (a) not safe (b) safe
7. 7.⏱️ repeat 6 times { buzzer ON; wait 600 ms; buzzer OFF; wait 700 ms }
   How many milliseconds does this take in all?
8. 8.🔋 3 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
9. 9.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) neither part (c) the if part (d) the else part
10. 10.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) to hide the circuit (c) to make it colourful (d) symbols are heavier
11. 11.Which job needs a temperature sensor? (a) warn of a gas leak (b) water a dry plant (c) keep an incubator warm (d) open blinds at sunrise
12. 12.🗺️ In an input → process → output plan, is “an alert on the phone” the input, the process or the output? (a) input (b) output (c) process
13. 13.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 44 °C. What is shown? (a) Cool (b) Warm (c) Hot
14. 14.⚙️ Which actuator would you use to show a status light? (a) a servo motor (b) a pump (c) a motor (d) an LED
15. 15.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V + R (c) I = R ÷ V (d) I = V ÷ R
16. 16.What does a resistor do? (a) glows using little power (b) limits the current (c) is a resistance knob (d) turns a fan or wheels
17. 17.True or false: “own switch for each bulb” is true of a series circuit. (a) True (b) False
18. 18.🔋 How many 3 V cells must be joined in series to give 6 V?
19. 19.🧮 Three equal 60 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
21. 21.⚡ Power tells us … (a) the length of a wire (b) the colour of light (c) energy used each second (d) the size of a cell
22. 22.🔍 Which is the odd one out? (a) share only needed data (b) turn off unused gadgets (c) reuse one password (d) install software updates
23. 23.🔍 Which sensor would you use to spot someone walking in? (a) a gas sensor (b) a light sensor (c) a motion sensor (d) a distance sensor
24. 24.🔋 4 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)? =
25. 25.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) bulb (b) voltmeter (c) battery (d) LED
26. 26.🔌 Is an LED an input or an output for a microcontroller? (a) input (b) output
27. 27.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) straight lines (c) dotted circles (d) wavy lines
28. 28.⚡ Which formula gives electric power? (a) P = V + I (b) P = I ÷ V (c) P = V ÷ I (d) P = V × I
29. 29.Which of these is not safe? (a) use small battery cells (b) take cells out after use (c) climb an electric pole (d) stay away from pylons
30. 30.Which drawing is the symbol for an LED? (a) triangle, bar and arrows (b) many long-short pairs (c) a small empty box (d) a plain rectangle
31. 31.Which job needs a sound sensor? (a) keep an incubator warm (b) switch on with a clap (c) make a parking alarm (d) switch on lamps at dusk
32. 32.🤖 Does a TV remote usually have a microcontroller inside? (a) No (b) Yes
33. 33.🧾 A family uses 180 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
34. 34.True or false: a brass key is a conductor. (a) True (b) False
35. 35.🧩 Which part changes electrical energy into movement? (a) an LED (b) a motor (c) a resistor (d) a fuse
36. 36.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
37. 37.🔺 A current of 40 mA flows when 18.8 V is joined across a resistor. What is its resistance (in ohms)?
38. 38.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
39. 39.🧮 Four equal 400 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
40. 40.True or false: to climb an electric pole is not safe. (a) False (b) True

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