Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 75 · 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.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) LED (b) voltmeter (c) junction (d) ammeter
2. 2.🌐 In an IoT system, which part acts on a command? (a) sensor (b) Wi-Fi (c) microcontroller (d) actuator
3. 3.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) zero (c) bigger (d) smaller
4. 4.Which job needs a display? (a) beep an alarm (b) spin a robot’s wheels (c) show a status light (d) show the temperature
5. 5.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 2200 Ω resistor? (a) red-red-orange (b) red-red-red (c) red-red-brown (d) red-orange-red
6. 6.🔋 A 9 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
7. 7.🔺 A current of 3 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
8. 8.🔌 Is aluminium foil a conductor or an insulator? (a) a conductor (b) an insulator
9. 9.🔁 repeat 5 times { repeat 5 times { beep } }
   How many beeps are there?
10. 10.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a brass key across the gap. Does the bulb glow? (a) Yes (b) No
11. 11.🤖 if (distance < 30) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 36 cm. What happens? (a) buzzer is silent (b) buzzer beeps
12. 12.🔍 Which is the odd one out? (a) reuse one password (b) share only needed data (c) change default passwords (d) set a strong password
13. 13.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire has come loose (d) the switch is ON
14. 14.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
15. 15.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the cloud stores it (b) it is sent by Wi-Fi (c) the app shows it (d) the sensor measures
16. 16.🔌 Is a rubber eraser a conductor or an insulator? (a) an insulator (b) a conductor
17. 17.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
18. 18.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
19. 19.🧾 A family uses 200 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
20. 20.Which job is done by the voltage regulator? (a) keeps the voltage steady (b) runs the program (c) restarts the program (d) brings power and code
21. 21.Which of these is safe? (a) use small battery cells (b) touch a fallen wire (c) touch a switch when wet (d) fly a kite near wires
22. 22.💡 What does LED stand for? (a) low energy device (b) light-emitting diode (c) large electric dial (d) light energy dial
23. 23.🔘 Which kind of switch slides side to side? (a) a push button (b) a tilt switch (c) a slide switch (d) a reed switch
24. 24.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
25. 25.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 80 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
26. 26.⚠️ Is it safe to take cells out after use? (a) safe (b) not safe
27. 27.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) the loop is complete (d) all wires are joined
28. 28.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 440 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
29. 29.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
30. 30.💡 5 identical bulbs are in parallel and each bulb has its own switch on its path. 4 of the switches are OFF and the rest are ON. How many bulbs glow?
31. 31.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 9 V (c) 1.5 V (d) 12 V
32. 32.Which of these is not safe? (a) keep drinks far away (b) poke things in a socket (c) stay away from pylons (d) fly kites in open fields
33. 33.📏 In the water-pipe picture of a circuit, voltage is like … (a) the pipe colour (b) the tap handle (c) the water tank lid (d) the water pressure
34. 34.🧮 Two equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
35. 35.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they all go out (c) they explode (d) they keep glowing
36. 36.True or false: to stop if a part gets hot is safe. (a) False (b) True
37. 37.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 ampere
38. 38.🔘 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) Yes (b) No
39. 39.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the glass (d) the base
40. 40.Which of these is safe? (a) poke things in a socket (b) build with an adult near (c) touch a fallen wire (d) open a phone charger

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