Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 41 · 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: a slide switch closes near a magnet. (a) False (b) True
2. 2.💡 4 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
3. 3.🔐 Is it a good or a risky habit to keep factory passwords? (a) risky habit (b) good habit
4. 4.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) True (b) False
5. 5.What does a tilt switch do? (a) springs back when let go (b) closes when tipped over (c) stays where you flip it (d) slides side to side
6. 6.True or false: a TV remote has no microcontroller inside. (a) True (b) False
7. 7.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a buzzer (c) a resistor (d) a diode
8. 8.True or false: resistance is measured in volts (V). (a) True (b) False
9. 9.⚡ Which formula gives electric power? (a) P = V + I (b) P = I ÷ V (c) P = V ÷ I (d) P = V × I
10. 10.⏱️ A program says “wait 9500 ms”. How many seconds is that? =
11. 11.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) a fuse (c) a power source (d) an output
12. 12.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 9 seconds?
13. 13.True or false: voltage is measured in amperes (A). (a) True (b) False
14. 14.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 230 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
15. 15.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
16. 16.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
17. 17.🔺 A 10 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
18. 18.🔍 Which sensor would you use to keep an incubator warm? (a) a gas sensor (b) a motion sensor (c) a temperature sensor (d) a soil moisture sensor
19. 19.🔁 repeat 3 times { repeat 5 times { beep } }
    How many beeps are there?
20. 20.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V + I (c) R = V × I (d) R = V ÷ I
21. 21.True or false: the ammeter is joined in series. (a) True (b) False
22. 22.⚙️ Which actuator would you use to open a gate to 90°? (a) a display (b) a motor (c) a pump (d) a servo motor
23. 23.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) stays the same (d) gets smaller
24. 24.🔋 5 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
25. 25.⚡ Power tells us … (a) the size of a cell (b) the length of a wire (c) energy used each second (d) the colour of light
26. 26.Which job needs a gas sensor? (a) switch on with a clap (b) stop a robot near walls (c) switch on lamps at dusk (d) warn of a gas leak
27. 27.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
28. 28.📏 Which unit measures energy used each second? (a) ohm (Ω) (b) watt (W) (c) volt (V) (d) ampere (A)
29. 29.🔋 What is a battery? (a) two or more cells joined (b) a kind of bulb (c) one single wire (d) a switch with a lid
30. 30.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is OFF and C is ON. Does the bulb glow? (a) No (b) Yes
31. 31.🔋 6 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)? =
32. 32.What does a motor do? (a) limits the current (b) stores a little charge (c) makes things spin (d) boosts a small signal
33. 33.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
34. 34.💡 A battery lights 4 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
35. 35.True or false: a circle with an X in it is the symbol for a cell. (a) True (b) False
36. 36.⚡ A device works on 24 V and takes 3 A. What is its power (in watts)? =
37. 37.🧮 A 1.8 V battery is joined to 6 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
38. 38.Which of these is the output? (a) a soil moisture reading (b) check if temp > 30 (c) the pump turns on (d) decide if soil is dry
39. 39.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
40. 40.🔍 Which is the odd one out? (a) poke things in a socket (b) touch a fallen wire (c) keep drinks far away (d) use mains for a project

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