Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 892 · 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 the output? (a) a soil moisture reading (b) a light level reading (c) decide if soil is dry (d) an LED lights up
2. 2.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
3. 3.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
4. 4.🔺 An 8 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
5. 5.🔍 Which is the odd one out? (a) a push button (b) a servo motor (c) a motion sensor (d) a light sensor
6. 6.🔋 How many volts does one ordinary torch cell give? (a) 0.5 V (b) 15 V (c) 230 V (d) 1.5 V
7. 7.Which job needs a motion sensor? (a) water a dry plant (b) spot someone walking in (c) stop a robot near walls (d) close a window in rain
8. 8.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) neither line (c) both lines (d) the longer line
9. 9.True or false: to stay away from pylons is not safe. (a) True (b) False
10. 10.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 10 (c) 100 (d) 60
11. 11.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) by Wi-Fi (c) not joined (d) in parallel
12. 12.🔍 Which is the odd one out? (a) open a phone charger (b) dry your hands first (c) fly kites in open fields (d) keep drinks far away
13. 13.True or false: a brass key is an insulator. (a) False (b) True
14. 14.🔐 Who should decide which smart devices go in a child’s room? (a) the app’s adverts (b) an online stranger (c) a parent or guardian (d) nobody at all
15. 15.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 2.5 V supply. What current flows (in mA)?
16. 16.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
17. 17.⏱️ repeat 5 times { buzzer ON; wait 100 ms; buzzer OFF; wait 700 ms }
    How many milliseconds does this take in all?
18. 18.Which drawing is the symbol for a diode? (a) triangle against a bar (b) a plain rectangle (c) a circle with M inside (d) a line lifted at a gap
19. 19.True or false: to open a phone charger is not safe. (a) False (b) True
20. 20.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) joins two wires (d) stores a value
22. 22.What does the cloud server do? (a) stores data online (b) shows data to you (c) carries the data (d) reads values, decides
23. 23.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) a full circuit (d) an open circuit
24. 24.🌈 A resistor has the colour bands green, orange, red. What is its value in kilo-ohms (kΩ)? =
25. 25.True or false: “a button: pressed or not” is an analog signal. (a) False (b) True
26. 26.True or false: a hand pump has no microcontroller inside. (a) True (b) False
27. 27.🔋 Does a power station give electricity or use electricity? (a) uses electricity (b) gives electricity
28. 28.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
29. 29.💡 A battery lights 3 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
30. 30.Which of these is measured in amperes (A)? (a) current (b) resistance (c) the push of a cell (d) voltage
31. 31.⚡ Which tiny particles drift along a metal wire to carry the current? (a) water drops (b) electrons (c) photons (d) dust particles
32. 32.🔍 Which is the odd one out? (a) a sound sensor (b) a light sensor (c) a motion sensor (d) a buzzer
33. 33.True or false: “a single current path” is true of a series circuit. (a) False (b) True
34. 34.True or false: “one bulb out, all go out” is true of a series circuit. (a) True (b) False
35. 35.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) never (b) only when both are ON (c) when either is ON (d) only when both are OFF
36. 36.🔍 Which is the odd one out? (a) a graphite rod (b) a steel coin (c) a safety pin (d) a glass marble
37. 37.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is ON and B is ON. Does the bulb glow? (a) Yes (b) No
38. 38.🧩 A capacitor in a circuit can … (a) store charge briefly (b) measure heat (c) make light (d) spin a wheel
39. 39.⚡ A device works on 3 V and takes 1.5 A. What is its power (in watts)? =
40. 40.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire has come loose (d) the loop is complete

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