Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 720 · 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: voltage is measured in volts (V). (a) False (b) True
2. 2.⚡ A device works on 1.5 V and takes 1 A. What is its power (in watts)? =
3. 3.⚙️ Which actuator would you use to move water to plants? (a) an LED (b) a display (c) a servo motor (d) a pump
4. 4.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a bulb (b) a fuse or MCB (c) a long wire (d) a plug top
5. 5.⏱️ loop forever { LED ON; wait 600 ms; LED OFF; wait 400 ms }
   How many times does the LED blink in 9 seconds?
6. 6.🌈 In the resistor colour code, which number does brown stand for?
7. 7.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
8. 8.Which of these is measured in volts (V)? (a) resistance (b) power (c) the push of a cell (d) energy used each second
9. 9.Which of these mainly gives out light? (a) a school bell (b) a buzzer (c) a street light (d) an exhaust fan
10. 10.🌈 In the resistor colour code, which number does blue stand for?
11. 11.Which of these is measured in ohms (Ω)? (a) energy used each second (b) the flow of charge (c) the push of a cell (d) how much a part resists
12. 12.True or false: to change default passwords is a risky habit. (a) False (b) True
13. 13.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
14. 14.🔐 Is it a good or a risky habit to post your live location? (a) risky habit (b) good habit
15. 15.🔌 Most metals are good … (a) insulators (b) magnets only (c) batteries (d) conductors
16. 16.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
17. 17.🌈 Which band is read first on a resistor? (a) the widest gap (b) the gold band (c) any band (d) the one nearest an end
18. 18.🔺 A current of 1.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
19. 19.🔋 How many 3 V cells must be joined in series to give 24 V?
20. 20.📏 Which unit measures energy used each second? (a) volt (V) (b) ampere (A) (c) watt (W) (d) ohm (Ω)
21. 21.🔋 How many 1.5 V cells must be joined in series to give 3 V?
22. 22.🔋 Does an air conditioner give electricity or use electricity? (a) gives electricity (b) uses electricity
23. 23.Which of these is a risky habit? (a) accept every permission (b) turn off unused gadgets (c) cover unused cameras (d) set a strong password
24. 24.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 1000 (c) 10 (d) 100
25. 25.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) neither line (c) both lines (d) the shorter line
26. 26.Which drawing is the symbol for a battery? (a) two or more cell symbols (b) a circle with an X in it (c) a line lifted at a gap (d) a straight line
27. 27.True or false: to keep factory passwords is a good habit. (a) True (b) False
28. 28.🔍 Which is the odd one out? (a) an LED lamp (b) a tube light (c) a torch (d) a ceiling fan
29. 29.💡 3 identical bulbs are joined in series with a 4.5 V battery (ideal wires). How many volts does each bulb get? =
30. 30.🔺 A 15 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
31. 31.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) always zero (c) their sum (d) more than either one
32. 32.⚡ A device works on 9 V and takes 0.25 A. What is its power (in watts)? =
33. 33.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 80 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
34. 34.⚡ Which tiny particles drift along a metal wire to carry the current? (a) photons (b) dust particles (c) electrons (d) water drops
35. 35.🔺 A 2.5 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
36. 36.🔁 x = 2
    repeat 5 times { x = x × 2 }
    What is x at the end?
37. 37.🔋 A 3 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
38. 38.Which of these is an insulator? (a) a steel coin (b) a brass key (c) aluminium foil (d) a paper strip
39. 39.🧾 A family uses 190 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
40. 40.🔘 When a switch is ON, the circuit is … (a) open (b) cut (c) closed (d) broken

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