Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 941 · 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: the push of a cell is measured in volts (V). (a) True (b) False
2. 2.🔺 A current of 3 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
3. 3.🗺️ In an input → process → output plan, is “a temperature reading” the input, the process or the output? (a) output (b) process (c) input
4. 4.🔋 4 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
5. 5.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 100 readings take?
6. 6.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 50 ms }
   How many times does the LED blink in 4 seconds?
7. 7.🔢 To plan an electronics project, which comes first: “test it and fix it” or “build it with an adult”? (a) build it with an adult (b) test it and fix it
8. 8.⏱️ loop forever { LED ON; wait 500 ms; LED OFF; wait 550 ms }
   How many milliseconds does one blink (ON + OFF) take?
9. 9.🔐 Which is the strongest password for a home smart camera? (a) 123456 (b) Tiger#Lamp42!Moon (c) password (d) admin
10. 10.🧮 Resistors of 220 Ω, 470 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
11. 11.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
12. 12.Which drawing is the symbol for a cell? (a) one tall, one short bar (b) two equal parallel lines (c) two or more cell symbols (d) a circle with A inside
13. 13.💡 2 identical bulbs are joined in series with a 2 V battery (ideal wires). How many volts does each bulb get? =
14. 14.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
15. 15.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
16. 16.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
17. 17.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
18. 18.True or false: a circle with V inside is the symbol for a switch. (a) True (b) False
19. 19.💡 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 1 glow? (a) No (b) Yes
20. 20.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 5 V supply. What current flows (in mA)?
21. 21.⚡ A 36 W device works on 12 V. What current does it take (in amperes)? =
22. 22.Which of these means the circuit is closed? (a) the switch is ON (b) the bulb is unscrewed (c) a cell is taken out (d) a wire is cut
23. 23.True or false: triangle, bar and arrows is the symbol for an LED. (a) False (b) True
24. 24.Which of these is an input? (a) a water pump (b) a push button (c) an LED (d) a speaker
25. 25.🔌 Why are electric wires covered in plastic? (a) plastic makes current (b) plastic is a conductor (c) plastic is an insulator (d) to make them heavy
26. 26.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) stores current (c) changes the voltage (d) makes electricity
27. 27.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 99000 Ω resistor? (a) white-black-orange (b) white-white-yellow (c) white-white-orange (d) white-white-red
28. 28.💡 Why does an LED need a resistor in series? (a) to store charge (b) to limit the current (c) to make it brighter (d) to change its colour
29. 29.🗺️ Before building a project, what should you write down first? (a) the box colour (b) inputs and outputs (c) nothing at all (d) the final price
30. 30.Which of these saves electricity? (a) use old filament bulbs (b) leave the TV on standby (c) unplug idle chargers (d) iron one shirt at a time
31. 31.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) No (b) Yes
32. 32.🔍 Which is the odd one out? (a) an electric iron (b) a toaster (c) an electric kettle (d) a table fan
33. 33.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
34. 34.🧩 Which component glows using little power? (a) LED (b) potentiometer (c) buzzer (d) diode
35. 35.Which of these is the process? (a) a light level reading (b) a temperature reading (c) decide if soil is dry (d) a soil moisture reading
36. 36.🔋 4 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)? =
37. 37.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) both of them (c) only one (d) none
38. 38.📏 In the water-pipe picture of a circuit, current is like … (a) the pipe colour (b) the water pressure (c) a narrow pipe (d) the flow of water
39. 39.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
40. 40.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel

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