Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 381 · 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 of these means the circuit is open? (a) the loop is complete (b) the switch is OFF (c) all wires are joined (d) the switch is ON
2. 2.🧾 A 500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
3. 3.True or false: a motor turns a fan or wheels. (a) False (b) True
4. 4.🤖 “if (A AND B)” is true when … (a) only B is true (b) only A is true (c) both are false (d) both A and B are true
5. 5.📶 How many states can a digital pin have? (a) ten (b) two (c) a thousand (d) one
6. 6.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 25 % (d) 5 %
7. 7.True or false: a microwave oven usually has a microcontroller inside. (a) False (b) True
8. 8.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) input (b) output (c) process
9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the glass (d) the base
10. 10.Which drawing is the symbol for a cell? (a) a dot where wires meet (b) triangle against a bar (c) many long-short pairs (d) a long and a short line
11. 11.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) joins two wires (d) stores a value
12. 12.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
13. 13.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “switch the pump on/off”? (a) compare with the limit (b) switch the pump on/off
14. 14.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
15. 15.💡 Why is house wiring done in parallel? (a) so all go off together (b) to save copper only (c) each gets full voltage (d) to make bulbs dim
16. 16.🔺 A current of 1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
17. 17.Which of these is the input? (a) an alert on the phone (b) a motion sensor signal (c) count button presses (d) check if temp > 30
18. 18.True or false: a rice cooker mainly makes sound. (a) True (b) False
19. 19.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
20. 20.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
21. 21.True or false: to change default passwords is a risky habit. (a) False (b) True
22. 22.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
23. 23.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
24. 24.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
25. 25.True or false: a loudspeaker mainly makes sound. (a) False (b) True
26. 26.⚡ What does an exhaust fan mainly change electricity into? (a) sound (b) light (c) heat (d) movement
27. 27.What does a tilt switch do? (a) slides side to side (b) springs back when let go (c) stays where you flip it (d) closes when tipped over
28. 28.⚡ A device works on 1.5 V and takes 1.5 A. What is its power (in watts)? =
29. 29.🧮 Two equal 330 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
30. 30.True or false: a potentiometer blows if current is high. (a) True (b) False
31. 31.🗺️ In an input → process → output plan, is “the fan starts” the input, the process or the output? (a) process (b) input (c) output
32. 32.🔘 Which kind of switch flips up or down? (a) a reed switch (b) a toggle switch (c) a slide switch (d) a tilt switch
33. 33.⏱️ A program says “wait 250 ms”. How many seconds is that? =
34. 34.True or false: a night lamp mainly gives out light. (a) True (b) False
35. 35.🌈 A resistor has the colour bands yellow, red, red. What is its value in kilo-ohms (kΩ)? =
36. 36.✏️ In a circuit diagram, which part is drawn as a circle with V inside? (a) diode (b) motor (c) bulb (d) voltmeter
37. 37.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 8 seconds?
38. 38.🧾 A family uses 190 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
39. 39.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the gold band (c) the widest gap (d) any band
40. 40.True or false: “own switch for each bulb” is true of a parallel circuit. (a) False (b) True

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