Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 837 · 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.🔐 Is it a good or a risky habit to log out of shared phones? (a) risky habit (b) good habit
2. 2.💡 2 identical bulbs are joined in parallel across a 4.5 V battery (ideal wires). How many volts does each bulb get? =
3. 3.Which of these is the process? (a) a temperature reading (b) a button press (c) decide if soil is dry (d) an alert on the phone
4. 4.True or false: a small empty box is the symbol for a capacitor. (a) False (b) True
5. 5.🤖 if (light < 400) { lamp ON } else { lamp OFF }
   The light sensor reads 495. What happens? (a) lamp ON (b) lamp OFF
6. 6.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a plastic ruler. Does the bulb glow? (a) Yes (b) No
7. 7.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the loop is complete (d) the switch is ON
8. 8.What does the cloud server do? (a) shows data to you (b) reads values, decides (c) measures the real world (d) stores data online
9. 9.True or false: a night lamp mainly gives out light. (a) True (b) False
10. 10.💡 In a series circuit, how many paths does the current have? (a) two (b) none (c) one for each bulb (d) one
11. 11.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
12. 12.Which of these is a conductor? (a) an iron nail (b) a wooden stick (c) a cotton thread (d) a plastic ruler
13. 13.🌈 In the resistor colour code, which number does grey stand for?
14. 14.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 volt (d) 1 kilowatt-hour (kWh)
15. 15.🧩 Which part changes electrical energy into movement? (a) a motor (b) a fuse (c) a resistor (d) an LED
16. 16.🧾 A family uses 50 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
17. 17.🔐 Is it a good or a risky habit to cover unused cameras? (a) good habit (b) risky habit
18. 18.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a buzzer (b) a display (c) a motor (d) a pump
19. 19.🔁 count = 1
    while (count < 29) { count = count + 4 }
    How many times does the loop run?
20. 20.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets smaller (c) becomes zero (d) gets bigger
21. 21.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
22. 22.What does a slide switch do? (a) slides side to side (b) stays where you flip it (c) springs back when let go (d) closes when tipped over
23. 23.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
24. 24.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
25. 25.🔺 A current of 2 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
27. 27.What does a tilt switch do? (a) works only while pressed (b) springs back when let go (c) closes when tipped over (d) stays where you flip it
28. 28.True or false: a motor has coloured bands. (a) False (b) True
29. 29.📏 Which unit measures the push of a cell? (a) ohm (Ω) (b) volt (V) (c) watt (W) (d) ampere (A)
30. 30.Which job is done by the power LED? (a) runs the program (b) keeps the voltage steady (c) shows the board is on (d) connect sensors and LEDs
31. 31.🔋 5 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)? =
32. 32.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
33. 33.🔢 To run one loop of a plant-watering program, which comes first: “wait a few seconds” or “switch the pump on/off”? (a) wait a few seconds (b) switch the pump on/off
34. 34.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) wavy lines (c) straight lines (d) dotted circles
35. 35.🔺 A 4 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
36. 36.Which job needs a gas sensor? (a) measure classroom noise (b) warn of a gas leak (c) switch on with a clap (d) make a parking alarm
37. 37.🌈 A resistor has the colour bands brown, green, red. What is its value (in ohms)?
38. 38.Which of these saves electricity? (a) use old filament bulbs (b) close the fridge quickly (c) run fans in empty rooms (d) leave fridge door open
39. 39.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) prints 1 (c) takes 1 away (d) sets count to 1
40. 40.⚠️ Is it safe to open a phone charger? (a) not safe (b) safe

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