Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 446 · 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 shorter leg is the anode (+). (a) True (b) False
2. 2.⚡ A cell changes stored chemical energy into which kind of energy? (a) wind energy (b) sound energy (c) nuclear energy (d) electrical energy
3. 3.⚡ What does a night lamp mainly change electricity into? (a) light (b) sound (c) heat (d) movement
4. 4.🤖 Where does the board keep its program when the power is off? (a) the USB cable (b) the resistor (c) the power LED (d) flash memory
5. 5.⏱️ loop forever { LED ON; wait 1000 ms; LED OFF; wait 200 ms }
   How many milliseconds does one blink (ON + OFF) take?
6. 6.🧮 Resistors of 100 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
7. 7.🤖 “if (A AND B)” is true when … (a) only B is true (b) both A and B are true (c) only A is true (d) both are false
8. 8.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 730 Ω resistor? (a) violet-orange-black (b) orange-violet-brown (c) violet-orange-brown (d) violet-orange-red
9. 9.⚡ What does a buzzer mainly change electricity into? (a) sound (b) movement (c) heat (d) light
10. 10.Which job needs a display? (a) move water to plants (b) beep an alarm (c) turn to an exact angle (d) show the temperature
11. 11.🔁 count = 3
    while (count < 43) { count = count + 5 }
    How many times does the loop run?
12. 12.🔍 Which is the odd one out? (a) use mains for a project (b) climb an electric pole (c) stay away from pylons (d) open a phone charger
13. 13.📏 How many watts (W) is 4.1 kW?
14. 14.🧾 A family uses 20 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
15. 15.⚡ What does a siren mainly change electricity into? (a) sound (b) light (c) movement (d) heat
16. 16.🔺 A current of 0.1 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.True or false: to build with an adult near is not safe. (a) True (b) False
18. 18.True or false: “HIGH or LOW only” is a digital signal. (a) True (b) False
19. 19.True or false: a steel coin is an insulator. (a) True (b) False
20. 20.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
21. 21.Which of these has no microcontroller inside? (a) a microwave oven (b) a toy robot (c) a wind-up toy (d) a TV remote
22. 22.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) own switch for each bulb (c) a single current path (d) bulbs share the voltage
23. 23.Which of these mainly makes movement? (a) a table fan (b) a loudspeaker (c) a night lamp (d) an LED lamp
24. 24.Which of these mainly gives out light? (a) a traffic signal (b) a doorbell (c) a ceiling fan (d) a table fan
25. 25.🔋 6 identical 3 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
26. 26.True or false: a toggle switch stays where you flip it. (a) True (b) False
27. 27.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is ON and B is OFF. Does the bulb glow? (a) No (b) Yes
28. 28.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 1 glow? (a) Yes (b) No
29. 29.🔌 Is a small display an input or an output for a microcontroller? (a) input (b) output
30. 30.🔺 A current of 2.5 A flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
31. 31.🔁 count = 3
    while (count < 11) { count = count + 4 }
    How many times does the loop run?
32. 32.⚡ A device works on 24 V and takes 1.5 A. What is its power (in watts)? =
33. 33.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) so all go off together (c) each gets full voltage (d) to save copper only
34. 34.Which of these is the output? (a) the pump turns on (b) a button press (c) a light level reading (d) check if temp > 30
35. 35.📶 How many states can a digital pin have? (a) one (b) ten (c) a thousand (d) two
36. 36.True or false: an LDR senses how bright it is. (a) False (b) True
37. 37.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
38. 38.True or false: a washing machine usually has a microcontroller inside. (a) False (b) True
39. 39.🔌 Is a push button an input or an output for a microcontroller? (a) output (b) input
40. 40.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it does not light (c) it makes a sound (d) it changes colour

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