Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 566 · 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.💡 Why does an LED need a resistor in series? (a) to change its colour (b) to limit the current (c) to make it brighter (d) to store charge
2. 2.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) energy used each second (d) the length of a wire
3. 3.True or false: “a tilt switch: on or off” is a digital signal. (a) True (b) False
4. 4.🧮 An 11 V battery is joined to 3 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
5. 5.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) neither part (d) the if part
6. 6.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 LOW
   set pin 7 HIGH
   set pin 7 LOW
   set pin 7 HIGH
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
7. 7.🧭 Which part of a microcontroller board restarts the program? (a) the voltage regulator (b) the power LED (c) the reset button (d) the USB port
8. 8.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 volt (c) 1 watt (d) 1 ampere
9. 9.🤖 Does a digital thermometer usually have a microcontroller inside? (a) No (b) Yes
10. 10.📏 Which unit measures voltage? (a) volt (V) (b) ohm (Ω) (c) ampere (A) (d) watt (W)
11. 11.Which of these is a conductor? (a) a paper strip (b) a cotton thread (c) a woollen thread (d) a copper wire
12. 12.What does an LDR do? (a) makes a beeping sound (b) blows if current is high (c) senses how bright it is (d) limits the current
13. 13.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a motor (c) an LED (d) a fuse
14. 14.Which of these is the output? (a) a light level reading (b) a soil moisture reading (c) decide if soil is dry (d) a buzzer beeps
15. 15.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 175. What happens? (a) lamp ON (b) lamp OFF
16. 16.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
17. 17.🔺 A current of 20 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
18. 18.🔋 A 6 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
19. 19.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the one nearest an end (d) the widest gap
20. 20.📏 How many kilowatts (kW) is 2000 W? =
21. 21.🗺️ In an input → process → output plan, is “decide if soil is dry” the input, the process or the output? (a) input (b) process (c) output
22. 22.Which of these is a good habit? (a) share the Wi-Fi key (b) accept every permission (c) set a strong password (d) keep factory passwords
23. 23.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
24. 24.🔍 Which is the odd one out? (a) count button presses (b) a soil moisture reading (c) a temperature reading (d) a light level reading
25. 25.🔋 Does a wind turbine give electricity or use electricity? (a) gives electricity (b) uses electricity
26. 26.🔍 Which is the odd one out? (a) a doorbell (b) a siren (c) a school bell (d) an exhaust fan
27. 27.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) ammeter (b) cell (c) diode (d) battery
28. 28.🔺 A 30 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
29. 29.Which of these is a conductor? (a) a ceramic cup (b) a paper strip (c) a graphite rod (d) a cotton thread
30. 30.Which of these is an output? (a) a push button (b) a sound sensor (c) a turning knob (d) a small display
31. 31.🤖 Does a digital alarm clock usually have a microcontroller inside? (a) No (b) Yes
32. 32.💡 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
33. 33.🔁 repeat 3 times { repeat 3 times { beep } }
    How many beeps are there?
34. 34.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 2 seconds?
35. 35.🔺 A current of 0.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
36. 36.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 21 °C. What is shown? (a) Warm (b) Hot (c) Cool
37. 37.🔌 Is a steel spoon a conductor or an insulator? (a) an insulator (b) a conductor
38. 38.Which of these is a risky habit? (a) keep factory passwords (b) turn off unused gadgets (c) set up with a parent (d) set a strong password
39. 39.📏 How many ohms (Ω) is 0.4 kΩ?
40. 40.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave fridge door open (c) use daylight to read (d) leave the TV on standby

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