Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 415 · 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.💡 A battery lights 4 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
2. 2.⏱️ repeat 9 times { buzzer ON; wait 300 ms; buzzer OFF; wait 800 ms }
   How many milliseconds does this take in all?
3. 3.True or false: the flow of charge is measured in amperes (A). (a) True (b) False
4. 4.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) the same voltage (c) a smaller voltage (d) a bigger voltage
5. 5.🔐 Is it a good or a risky habit to set a strong password? (a) risky habit (b) good habit
6. 6.🔍 An object is 68 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
7. 7.⚡ A device works on 5 V and takes 0.1 A. What is its power (in watts)? =
8. 8.🧮 Resistors of 150 Ω, 330 Ω, 220 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
9. 9.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a safety pin across the gap. Does the bulb glow? (a) Yes (b) No
10. 10.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 44. What happens? (a) green LED ON (b) red LED ON
11. 11.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
12. 12.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) never (c) when both are ON (d) when both are OFF
13. 13.⚡ A device works on 24 V and takes 0.1 A. What is its power (in watts)? =
14. 14.🔍 Which is the odd one out? (a) check if temp > 30 (b) the fan starts (c) an LED lights up (d) an alert on the phone
15. 15.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) tell it your passwords (b) put it in the bathroom (c) mute it when not in use (d) let strangers use it
16. 16.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) bulb (b) resistor (c) cell (d) diode
17. 17.🔋 Does a mobile phone give electricity or use electricity? (a) uses electricity (b) gives electricity
18. 18.Which drawing is the symbol for an LED? (a) triangle, bar and arrows (b) a line lifted at a gap (c) a circle with M inside (d) a circle with an X in it
19. 19.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 10 (c) 1000 (d) 60
20. 20.🌈 In the resistor colour code, which number does brown stand for?
21. 21.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
22. 22.True or false: a spinning top has no microcontroller inside. (a) True (b) False
23. 23.True or false: “compare with a limit” is the process. (a) False (b) True
24. 24.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 6.5 V supply. What current flows (in mA)?
25. 25.True or false: “one out, the rest glow” is true of a series circuit. (a) True (b) False
26. 26.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) an open circuit (b) a short circuit (c) a safe circuit (d) a parallel circuit
27. 27.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) True (b) False
28. 28.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) bulb (b) resistor (c) ammeter (d) cell
29. 29.🌈 In the resistor colour code, which number does white stand for?
30. 30.💡 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 2 glow? (a) Yes (b) No
31. 31.Which job needs a temperature sensor? (a) stop a robot near walls (b) water a dry plant (c) switch on with a clap (d) keep an incubator warm
32. 32.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) resistor (b) switch (c) ammeter (d) capacitor
33. 33.🔐 Which is the strongest password for a home smart camera? (a) Tiger#Lamp42!Moon (b) admin (c) 123456 (d) password
34. 34.⚡ What does a traffic signal mainly change electricity into? (a) light (b) movement (c) heat (d) sound
35. 35.💡 A battery lights 5 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
36. 36.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) in series (c) not joined (d) in parallel
37. 37.Which of these is an output? (a) a temperature sensor (b) a sound sensor (c) an LED (d) a turning knob
38. 38.✏️ In a circuit diagram, which part is drawn as a circle with a cross? (a) ammeter (b) cell (c) voltmeter (d) bulb
39. 39.🧮 A 33 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
40. 40.⚡ A solar panel changes which kind of energy into electricity? (a) light energy (b) wind energy (c) chemical energy (d) sound energy

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