Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 564 · 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: a wooden stick is an insulator. (a) False (b) True
2. 2.🔌 A gap of dry air between two wires acts as … (a) a cell (b) a switch that is ON (c) a conductor (d) an insulator
3. 3.⚙️ Which actuator would you use to beep an alarm? (a) a display (b) a motor (c) a servo motor (d) a buzzer
4. 4.🔁 x = 2
   repeat 5 times { x = x × 2 }
   What is x at the end?
5. 5.⚡ What does a room heater mainly change electricity into? (a) heat (b) sound (c) light (d) movement
6. 6.⚡ A device works on 3 V and takes 0.1 A. What is its power (in watts)? =
7. 7.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) energy used each second (d) the size of a cell
8. 8.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
9. 9.🔋 8 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)? =
10. 10.🌈 In the resistor colour code, which number does brown stand for?
11. 11.🔺 A current of 50 mA flows when 23.5 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) so all go off together (d) each gets full voltage
13. 13.⏱️ loop forever { LED ON; wait 250 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 6 seconds?
14. 14.🔘 Two switches are in series. When does the bulb glow? (a) when both are ON (b) never (c) when either is ON (d) when both are OFF
15. 15.🧾 A family uses 140 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
16. 16.True or false: a push button springs back when let go. (a) False (b) True
17. 17.⚡ A 0.3 W device works on 1.5 V. What current does it take (in amperes)? =
18. 18.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
19. 19.🌐 Is a pencil sharpener an IoT device? (a) not an IoT device (b) an IoT device
20. 20.⏱️ A program says “wait 1500 ms”. How many seconds is that? =
21. 21.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
22. 22.⏱️ How many milliseconds is a wait of 3.2 seconds?
23. 23.⚠️ Is it safe to stop if a part gets hot? (a) safe (b) not safe
24. 24.📏 Which unit measures current? (a) watt (W) (b) ohm (Ω) (c) ampere (A) (d) volt (V)
25. 25.🔌 Which part of a screwdriver should an electrician hold? (a) the bare end (b) the metal tip (c) the plastic handle (d) the steel shaft
26. 26.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 volt (c) 1 watt (d) 1 ampere
27. 27.🌈 Which band is read first on a resistor? (a) any band (b) the widest gap (c) the one nearest an end (d) the gold band
28. 28.🤖 Does a smart watch usually have a microcontroller inside? (a) No (b) Yes
29. 29.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) a wire is cut (d) a wire has come loose
30. 30.Which drawing is the symbol for a voltmeter? (a) a straight line (b) a circle with V inside (c) triangle against a bar (d) a long and a short line
31. 31.🔁 x = 2
    repeat 3 times { x = x × 2 }
    What is x at the end?
32. 32.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 5 seconds?
33. 33.🔍 Which is the odd one out? (a) use LED lamps (b) set the AC to 24 °C (c) unplug idle chargers (d) leave fridge door open
34. 34.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
35. 35.True or false: “count button presses” is the input. (a) False (b) True
36. 36.🧩 A capacitor in a circuit can … (a) store charge briefly (b) make light (c) spin a wheel (d) measure heat
37. 37.Which of these is not an IoT device? (a) an app-controlled bulb (b) a battery torch (c) a Wi-Fi smart plug (d) a fitness band with app
38. 38.🔺 A 1.5 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
39. 39.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) Yes (b) No
40. 40.🔺 A current of 0.25 A flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?

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