Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 226 · 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.⚠️ About how many volts do home sockets in India supply? (a) 12 V (b) 230 V (c) 9 V (d) 1.5 V
2. 2.🔋 Does a generator give electricity or use electricity? (a) gives electricity (b) uses electricity
3. 3.🔺 A current of 0.2 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) no voltage (c) half the voltage (d) the same voltage
5. 5.🔋 2 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
6. 6.⚠️ Is it safe to build with an adult near? (a) not safe (b) safe
7. 7.Which drawing is the symbol for a resistor? (a) a circle with M inside (b) one tall, one short bar (c) a line lifted at a gap (d) a small empty box
8. 8.Which of these is an insulator? (a) a copper wire (b) a metal paper clip (c) an iron nail (d) a wooden stick
9. 9.True or false: to warn of a gas leak, use a gas sensor. (a) True (b) False
10. 10.Which of these mainly makes movement? (a) an electric drill (b) a doorbell (c) a school bell (d) a siren
11. 11.📏 Which unit measures current? (a) volt (V) (b) ampere (A) (c) ohm (Ω) (d) watt (W)
12. 12.🔌 Is a brass key a conductor or an insulator? (a) a conductor (b) an insulator
13. 13.🧮 A 47 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
14. 14.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
15. 15.Which of these is true of a series circuit? (a) bulbs share the voltage (b) own switch for each bulb (c) used in house wiring (d) many paths for current
16. 16.True or false: to reuse one password is a risky habit. (a) False (b) True
17. 17.🔁 count = 0
    while (count < 14) { count = count + 2 }
    How many times does the loop run?
18. 18.Which of these is an IoT device? (a) a paper calendar (b) a plain table fan (c) a battery torch (d) a Wi-Fi smart plug
19. 19.🧩 Which component lets current go one way? (a) buzzer (b) resistor (c) transistor (d) diode
20. 20.🔍 Which is the odd one out? (a) aluminium foil (b) a copper wire (c) a brass key (d) a ceramic cup
21. 21.True or false: an LED glows using little power. (a) False (b) True
22. 22.🔺 A current of 0.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🔍 Which is the odd one out? (a) a water pump (b) an LED (c) a motion sensor (d) a motor
24. 24.⚙️ Which actuator would you use to open a gate to 90°? (a) a pump (b) a motor (c) a display (d) a servo motor
25. 25.🏠 Which is a smart-home example? (a) lights on from an app (b) a hand fan (c) a printed map (d) a candle in a jar
26. 26.⚡ A device works on 1.5 V and takes 0.25 A. What is its power (in watts)? =
27. 27.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = R ÷ V (c) I = V × R (d) I = V ÷ R
28. 28.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
29. 29.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
30. 30.True or false: to fly kites in open fields is safe. (a) False (b) True
31. 31.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) blinks 500 times (c) pauses for half a second (d) waits 500 seconds
32. 32.🔌 Is a glass marble a conductor or an insulator? (a) a conductor (b) an insulator
33. 33.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 14000 Ω resistor? (a) brown-yellow-yellow (b) yellow-brown-orange (c) brown-yellow-red (d) brown-yellow-orange
34. 34.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
35. 35.True or false: how much a part resists is measured in watts (W). (a) False (b) True
36. 36.🧩 Which component smooths a wobbly supply? (a) resistor (b) capacitor (c) LED (d) LDR
37. 37.🔁 total = 0
    for i = 1 to 8 { total = total + i }
    What is total at the end?
38. 38.True or false: “many paths for current” is true of a series circuit. (a) True (b) False
39. 39.🤖 if (sound > 70) { red LED ON } else { green LED ON }
    The sound sensor reads 50. What happens? (a) green LED ON (b) red LED ON
40. 40.Which of these means the circuit is closed? (a) all wires are joined (b) a wire is cut (c) the bulb is unscrewed (d) a cell is taken out

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