Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 505 · 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.🔐 Is it a good or a risky habit to share only needed data? (a) good habit (b) risky habit
2. 2.True or false: a laptop has a built-in keyboard. (a) True (b) False
3. 3.🔋 Does a solar panel give electricity or use electricity? (a) uses electricity (b) gives electricity
4. 4.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
5. 5.⏱️ How many milliseconds is a wait of 0.4 seconds?
6. 6.🌈 A resistor has the colour bands white, blue, red. What is its value in kilo-ohms (kΩ)? =
7. 7.🔋 5 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
8. 8.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
9. 9.True or false: “a break stops every bulb” is true of a parallel circuit. (a) False (b) True
10. 10.🔺 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
11. 11.🏠 Which is a smart-home example? (a) a candle in a jar (b) a hand fan (c) lights on from an app (d) a printed map
12. 12.🔌 Is a dry cork a conductor or an insulator? (a) a conductor (b) an insulator
13. 13.🔋 How many 2 V cells must be joined in series to give 8 V?
14. 14.🔋 5 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
15. 15.🔋 3 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
16. 16.⚡ Which tiny particles drift along a metal wire to carry the current? (a) electrons (b) photons (c) water drops (d) dust particles
17. 17.🌐 What does IoT stand for? (a) Inside of Toys (b) Input of Tools (c) Internet of Things (d) Internet of Talk
18. 18.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
19. 19.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) battery (b) diode (c) wire (d) ammeter
20. 20.🔺 A 20 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
21. 21.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is OFF, B is ON, C is OFF and D is OFF. Does the bulb glow? (a) Yes (b) No
22. 22.Which drawing is the symbol for an ammeter? (a) one tall, one short bar (b) many long-short pairs (c) a line lifted at a gap (d) a circle with A inside
23. 23.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the widest gap (d) the one nearest an end
24. 24.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets smaller (d) gets bigger
25. 25.🔁 count = 1
    repeat 2 times { count = count + 7 }
    What is count at the end?
26. 26.Which job needs a distance sensor? (a) switch on lamps at dusk (b) spot someone walking in (c) make a parking alarm (d) start a fan when hot
27. 27.True or false: a push button flips up or down. (a) False (b) True
28. 28.🔍 A distance sensor sends a sound pulse and hears the echo 15 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
29. 29.⚠️ Why must we never touch switches with wet hands? (a) it spoils the paint (b) it is just untidy (c) water carries current (d) water makes it cold
30. 30.💡 An LED is joined to a 3 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) does not light (b) lights up (c) may burn out
31. 31.⏱️ How many milliseconds is a wait of 1.4 seconds?
32. 32.True or false: one tall, one short bar is the symbol for a cell. (a) True (b) False
33. 33.Which of these mainly gives out heat? (a) a torch (b) a water heater (c) a school bell (d) a loudspeaker
34. 34.🧭 Which part of a microcontroller board shows the board is on? (a) the pins (b) the USB port (c) the voltage regulator (d) the power LED
35. 35.🔐 Is it a good or a risky habit to set a strong password? (a) risky habit (b) good habit
36. 36.Which job needs a display? (a) open a gate to 90° (b) beep an alarm (c) show the temperature (d) move water to plants
37. 37.🔁 count = 7
    repeat 5 times { count = count + 6 }
    What is count at the end?
38. 38.🔋 What is a battery? (a) two or more cells joined (b) a switch with a lid (c) a kind of bulb (d) one single wire
39. 39.🗺️ In an input → process → output plan, is “check if temp > 30” the input, the process or the output? (a) input (b) process (c) output
40. 40.Which of these is safe? (a) take cells out after use (b) climb an electric pole (c) poke things in a socket (d) open a phone charger

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