Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 363 · 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 washing machine usually has a microcontroller inside. (a) True (b) False
2. 2.💡 What does LED stand for? (a) light-emitting diode (b) light energy dial (c) low energy device (d) large electric dial
3. 3.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) cell (b) junction (c) resistor (d) LED
4. 4.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I × R (c) V = I ÷ R (d) V = I + R
5. 5.🔺 A 12 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
6. 6.🔺 A current of 25 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
7. 7.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they explode (c) they get dimmer (d) they keep glowing
8. 8.⚡ What does a tube light mainly change electricity into? (a) light (b) movement (c) sound (d) heat
9. 9.🔺 A current of 50 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
10. 10.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
11. 11.Which drawing is the symbol for a switch? (a) triangle against a bar (b) a line lifted at a gap (c) a straight line (d) two equal parallel lines
12. 12.🤖 Microcontroller or laptop: which one has no screen of its own? (a) laptop (b) microcontroller
13. 13.🧩 Which component senses how bright it is? (a) LDR (b) diode (c) motor (d) fuse
14. 14.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V + R (c) I = R ÷ V (d) I = V ÷ R
15. 15.Which of these is true of a series circuit? (a) own switch for each bulb (b) each gets the full volts (c) used in house wiring (d) bulbs share the voltage
16. 16.🔌 Is a cotton thread a conductor or an insulator? (a) an insulator (b) a conductor
17. 17.True or false: a capacitor stores a little charge. (a) False (b) True
18. 18.True or false: “a light level reading” is the output. (a) False (b) True
19. 19.🧾 A family uses 100 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
20. 20.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
21. 21.🧩 Which component limits the current? (a) LDR (b) resistor (c) thermistor (d) capacitor
22. 22.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a plug top (b) a fuse or MCB (c) a long wire (d) a bulb
23. 23.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a series circuit (d) a closed circuit
24. 24.🔌 Which metal is used for most electric wires at home? (a) glass (b) copper (c) plastic (d) rubber
25. 25.True or false: to reuse one password is a good habit. (a) True (b) False
26. 26.🔘 When a switch is ON, the circuit is … (a) closed (b) open (c) cut (d) broken
27. 27.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
28. 28.🔺 A 1.5 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
29. 29.⚡ A 0.75 W device works on 3 V. What current does it take (in amperes)? =
30. 30.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
31. 31.Which of these is an IoT device? (a) a wind-up clock (b) an app-controlled bulb (c) a battery torch (d) a pencil sharpener
32. 32.🧭 Which part of a microcontroller board runs the program? (a) the reset button (b) the USB port (c) the pins (d) the main chip
33. 33.⚠️ Which power source should children use for electronics projects? (a) a wall socket (b) a mains extension board (c) an inverter socket (d) a small battery pack
34. 34.🧮 A 20 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
35. 35.⏱️ repeat 3 times { buzzer ON; wait 300 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
36. 36.True or false: to use mains for a project is not safe. (a) False (b) True
37. 37.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) False (b) True
38. 38.🗺️ In an input → process → output plan, is “the pump turns on” the input, the process or the output? (a) input (b) process (c) output
39. 39.⚡ What does an exhaust fan mainly change electricity into? (a) heat (b) light (c) sound (d) movement
40. 40.True or false: on a cell, “the flat end” means the − (negative) end. (a) False (b) True

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