Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 608 · 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: on an LED, the longer leg is the cathode (−). (a) False (b) True
2. 2.💡 An LED is joined to a 3 V battery through a 220 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) lights up (b) may burn out (c) does not light
3. 3.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) capacitor (b) switch (c) junction (d) cell
4. 4.🔍 Which is the odd one out? (a) a plastic ruler (b) a paper strip (c) a wooden stick (d) an iron nail
5. 5.True or false: a copper wire is a conductor. (a) True (b) False
6. 6.Which of these is a conductor? (a) a woollen thread (b) a plastic ruler (c) a copper wire (d) a dry cork
7. 7.🔋 How many 3 V cells must be joined in series to give 6 V?
8. 8.What does a slide switch do? (a) works only while pressed (b) closes when tipped over (c) slides side to side (d) flips up or down
9. 9.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) measure heat (d) spin a wheel
10. 10.🔺 A current of 50 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
11. 11.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
12. 12.🔋 What should you do with used-up cells? (a) throw them in a fire (b) cut them open (c) bury them in soil (d) give them for recycling
13. 13.🧾 A family uses 130 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
14. 14.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) the switch is OFF (d) all wires are joined
15. 15.🔍 Which is the odd one out? (a) a motor (b) a water pump (c) a motion sensor (d) an LED
16. 16.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 390 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
17. 17.🌈 A resistor has the colour bands green, orange, orange. What is its value in kilo-ohms (kΩ)? =
18. 18.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
19. 19.⚡ What does a table fan mainly change electricity into? (a) light (b) sound (c) movement (d) heat
20. 20.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
21. 21.🔁 count = 2
    while (count < 8) { count = count + 2 }
    How many times does the loop run?
22. 22.Which of these mainly makes sound? (a) a doorbell (b) a table fan (c) an LED lamp (d) an electric iron
23. 23.Which job needs a gas sensor? (a) open blinds at sunrise (b) start a fan when hot (c) warn of a gas leak (d) make a parking alarm
24. 24.🔐 Is it a good or a risky habit to change default passwords? (a) risky habit (b) good habit
25. 25.🔍 Which is the odd one out? (a) a smart energy meter (b) a battery torch (c) a pencil sharpener (d) a plain wall switch
26. 26.🔌 Is a ceramic cup a conductor or an insulator? (a) an insulator (b) a conductor
27. 27.True or false: “each gets the full volts” is true of a series circuit. (a) True (b) False
28. 28.🔍 Which is the odd one out? (a) fly kites in open fields (b) touch a switch when wet (c) keep drinks far away (d) build with an adult near
29. 29.📏 Voltmeter or ammeter: which one measures current? (a) ammeter (b) voltmeter
30. 30.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 3 seconds?
31. 31.True or false: triangle against a bar is the symbol for a motor. (a) False (b) True
32. 32.🔐 Why install updates on IoT devices? (a) they make it heavier (b) they delete the Wi-Fi (c) they fix security holes (d) they change the colour
33. 33.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when either is ON (c) when both are OFF (d) when both are ON
34. 34.🔍 Which is the odd one out? (a) a steel spoon (b) a plastic straw (c) a brass key (d) a safety pin
35. 35.🌐 What does IoT stand for? (a) Internet of Talk (b) Input of Tools (c) Internet of Things (d) Inside of Toys
36. 36.True or false: “each gets the full volts” is true of a parallel circuit. (a) True (b) False
37. 37.🧾 A family uses 90 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
38. 38.Which of these mainly makes movement? (a) an LED lamp (b) a tube light (c) a street light (d) a ceiling fan
39. 39.💡 An LED is joined to a 3 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) may burn out (c) lights up
40. 40.💡 In a series circuit, how many paths does the current have? (a) two (b) one for each bulb (c) none (d) one

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