Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 807 · 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 line lifted at a gap is the symbol for an LED. (a) True (b) False
2. 2.⚡ A 7.5 W device works on 5 V. What current does it take (in amperes)? =
3. 3.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) both parts (c) the if part (d) the else part
4. 4.🔁 count = 5
   while (count < 13) { count = count + 2 }
   How many times does the loop run?
5. 5.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 750 Ω resistor? (a) violet-green-red (b) violet-green-black (c) green-violet-brown (d) violet-green-brown
6. 6.💡 3 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 3 glow? (a) Yes (b) No
7. 7.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V + I (d) P = V × I
8. 8.True or false: a bicycle bell usually has a microcontroller inside. (a) True (b) False
9. 9.🔌 Is an LED an input or an output for a microcontroller? (a) output (b) input
10. 10.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
11. 11.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
12. 12.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I + R (c) V = R ÷ I (d) V = I × R
13. 13.True or false: a circle with an X in it is the symbol for a bulb. (a) False (b) True
14. 14.🔁 count = 2
    repeat 5 times { count = count + 3 }
    What is count at the end?
15. 15.📏 How many milliamperes (mA) is 2.68 A?
16. 16.🌐 A weather station sends one reading every 30 seconds. How many readings does it send in 8 minutes?
17. 17.Which of these is a good habit? (a) ignore update messages (b) change default passwords (c) share the Wi-Fi key (d) share camera links
18. 18.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
19. 19.Which job needs a light sensor? (a) stop a robot near walls (b) start a fan when hot (c) switch on with a clap (d) open blinds at sunrise
20. 20.⚡ What does an electric kettle mainly change electricity into? (a) movement (b) light (c) heat (d) sound
21. 21.🤖 “if (A AND B)” is true when … (a) both are false (b) both A and B are true (c) only B is true (d) only A is true
22. 22.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a rubber band. Does the bulb glow? (a) Yes (b) No
23. 23.Which drawing is the symbol for an ammeter? (a) a small empty box (b) two or more cell symbols (c) a circle with A inside (d) many long-short pairs
24. 24.🔍 Which is the odd one out? (a) an LED (b) a motor (c) a speaker (d) a temperature sensor
25. 25.True or false: to turn off unused gadgets is a risky habit. (a) False (b) True
26. 26.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
27. 27.🗺️ In an input → process → output plan, is “an LED lights up” the input, the process or the output? (a) input (b) process (c) output
28. 28.💡 4 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
29. 29.🔍 Which is the odd one out? (a) a tube light (b) an electric kettle (c) a traffic signal (d) a street light
30. 30.🔋 3 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
31. 31.💡 A battery lights 5 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
32. 32.🔁 count = 5
    repeat 10 times { count = count + 3 }
    What is count at the end?
33. 33.Which of these is true of a series circuit? (a) a break stops every bulb (b) many paths for current (c) one out, the rest glow (d) used in house wiring
34. 34.🌈 A resistor has the colour bands red, blue, orange. What is its value in kilo-ohms (kΩ)? =
35. 35.🔺 A current of 0.1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.🧮 Three equal 60 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
37. 37.🔋 2 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
38. 38.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
39. 39.Which of these is a good habit? (a) reuse one password (b) turn off unused gadgets (c) share the Wi-Fi key (d) post your live location
40. 40.🔐 Who should decide which smart devices go in a child’s room? (a) an online stranger (b) the app’s adverts (c) a parent or guardian (d) nobody at all

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