Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 562 · 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.Which of these is a conductor? (a) a wooden stick (b) a safety pin (c) a glass marble (d) a plastic ruler
2. 2.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a plug top (b) a fuse or MCB (c) a bulb (d) a long wire
3. 3.True or false: a reed switch flips up or down. (a) True (b) False
4. 4.🔢 To plan an electronics project, which is the LAST step? (a) list inputs and outputs (b) test it and fix it (c) pick a problem to solve (d) build it with an adult
5. 5.💡 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 8 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
6. 6.🔺 A current of 1 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
7. 7.🔍 Which is the odd one out? (a) share camera links (b) log out of shared phones (c) tap unknown app links (d) keep factory passwords
8. 8.True or false: on an LED, the longer leg is the anode (+). (a) False (b) True
9. 9.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a wire is cut
10. 10.🔍 A distance sensor sends a sound pulse and hears the echo 20 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
11. 11.🔺 A current of 25 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
12. 12.True or false: two equal parallel lines is the symbol for a switch. (a) True (b) False
13. 13.🧮 Resistors of 22 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
14. 14.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) quick and clear for all (c) to hide the circuit (d) symbols are heavier
15. 15.True or false: resistance is measured in ohms (Ω). (a) False (b) True
16. 16.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) type it all in (b) share it with friends (c) post it online (d) ask a parent first
17. 17.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V × R (c) I = V + R (d) I = V ÷ R
18. 18.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
19. 19.Which of these is a conductor? (a) a rubber band (b) an iron nail (c) a paper strip (d) a plastic ruler
20. 20.🧮 Three equal 300 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.What does a slide switch do? (a) flips up or down (b) closes when tipped over (c) slides side to side (d) springs back when let go
22. 22.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
23. 23.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) electric current (c) a magnet (d) friction
24. 24.🔘 A bulb and a cell are joined through 5 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
25. 25.🔐 Is it a good or a risky habit to keep factory passwords? (a) risky habit (b) good habit
26. 26.🔺 A current of 0.25 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
27. 27.🔁 repeat 5 times { repeat 3 times { beep } }
    How many beeps are there?
28. 28.🔍 An object is 136 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
29. 29.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
30. 30.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I × R (c) V = I + R (d) V = I ÷ R
31. 31.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) when both are ON (c) never (d) when either is ON
32. 32.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
33. 33.⏱️ A program says “wait 3250 ms”. How many seconds is that? =
34. 34.🔌 Is a steel spoon a conductor or an insulator? (a) a conductor (b) an insulator
35. 35.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) motor (b) LED (c) junction (d) battery
36. 36.🌈 A resistor has the colour bands blue, green, orange. What is its value in kilo-ohms (kΩ)? =
37. 37.📏 How many milliamperes (mA) is 1.51 A?
38. 38.⚡ A 6 W device works on 6 V. What current does it take (in amperes)? =
39. 39.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) both lines (c) neither line (d) the longer line
40. 40.🧮 Four equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?

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