Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 493 · 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.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
2. 2.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
3. 3.True or false: the voltmeter is joined across a part. (a) True (b) False
4. 4.Which of these is safe? (a) take cells out after use (b) open a phone charger (c) use mains for a project (d) touch a fallen wire
5. 5.🔐 Is it a good or a risky habit to turn off unused gadgets? (a) risky habit (b) good habit
6. 6.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) an app-controlled bulb (c) a smart energy meter (d) a pencil sharpener
7. 7.🤖 “if (A AND B)” is true when … (a) both are false (b) both A and B are true (c) only A is true (d) only B is true
8. 8.🌈 A resistor has the colour bands brown, black, black. What is its value (in ohms)?
9. 9.⚡ A 0.75 W device works on 3 V. What current does it take (in amperes)? =
10. 10.True or false: a laptop has a built-in keyboard. (a) True (b) False
11. 11.🔺 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
12. 12.🔁 count = 3
    while (count < 27) { count = count + 3 }
    How many times does the loop run?
13. 13.📏 How many watts (W) is 0.4 kW?
14. 14.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) compare with the limit (b) wait a few seconds (c) switch the pump on/off
15. 15.Which of these mainly gives out heat? (a) a loudspeaker (b) an exhaust fan (c) a school bell (d) an electric iron
16. 16.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) not an IoT device (b) an IoT device
17. 17.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave fridge door open (c) close the fridge quickly (d) iron one shirt at a time
18. 18.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
19. 19.What does a toggle switch do? (a) closes when tipped over (b) springs back when let go (c) closes near a magnet (d) stays where you flip it
20. 20.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 55 Ω resistor? (a) green-green-brown (b) blue-green-black (c) green-blue-black (d) green-green-black
21. 21.🔺 A current of 2 A flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
22. 22.🌈 In the resistor colour code, which number does green stand for?
23. 23.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
24. 24.🔌 Most metals are good … (a) magnets only (b) batteries (c) insulators (d) conductors
25. 25.🔁 count = 5
    while (count < 29) { count = count + 4 }
    How many times does the loop run?
26. 26.⚡ What does a night lamp mainly change electricity into? (a) heat (b) light (c) sound (d) movement
27. 27.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
28. 28.Which of these uses electricity? (a) a cell (b) a solar panel (c) a battery (d) a refrigerator
29. 29.Which of these is safe? (a) open a phone charger (b) stay away from pylons (c) poke things in a socket (d) throw cells in a fire
30. 30.Which job needs a soil moisture sensor? (a) water a dry plant (b) measure classroom noise (c) make a parking alarm (d) spot someone walking in
31. 31.What does the actuator do? (a) shows data to you (b) carries the data (c) stores data online (d) acts on a command
32. 32.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
33. 33.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
34. 34.⚠️ Is it safe to touch a switch when wet? (a) safe (b) not safe
35. 35.🔁 count = 5
    while (count < 17) { count = count + 2 }
    How many times does the loop run?
36. 36.🔺 A 0.2 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
37. 37.Which of these gives us electricity? (a) a refrigerator (b) an air conditioner (c) a mobile phone (d) a cell
38. 38.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 3700 Ω resistor? (a) orange-violet-brown (b) orange-violet-red (c) orange-violet-orange (d) violet-orange-red
39. 39.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) input (b) process (c) output
40. 40.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) movement energy (b) light energy (c) chemical energy (d) sound energy

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