Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 978 · 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 gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 25 % (d) 5 %
2. 2.True or false: resistance is measured in watts (W). (a) True (b) False
3. 3.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 7 HIGH
   set pin 7 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
4. 4.🔐 Is it a good or a risky habit to log out of shared phones? (a) good habit (b) risky habit
5. 5.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the widest gap (c) the gold band (d) any band
6. 6.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
7. 7.True or false: a dot where wires meet is the symbol for a bulb. (a) True (b) False
8. 8.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
9. 9.Which of these is the process? (a) a soil moisture reading (b) the fan starts (c) a temperature reading (d) compare with a limit
10. 10.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 610 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
11. 11.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
12. 12.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) bigger (d) stay the same
13. 13.🔋 2 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
14. 14.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 540 Ω resistor? (a) yellow-green-brown (b) green-yellow-red (c) green-yellow-brown (d) green-yellow-black
15. 15.🔌 Is a keypad an input or an output for a microcontroller? (a) output (b) input
16. 16.🔌 Why are electric wires covered in plastic? (a) plastic is a conductor (b) to make them heavy (c) plastic makes current (d) plastic is an insulator
17. 17.🔍 Which is the odd one out? (a) a servo motor (b) a temperature sensor (c) a speaker (d) a water pump
18. 18.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
19. 19.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) Yes (b) No
20. 20.🔍 Which is the odd one out? (a) keep factory passwords (b) share only needed data (c) set up with a parent (d) cover unused cameras
21. 21.Which of these gives us electricity? (a) a mobile phone (b) an air conditioner (c) a computer (d) a power station
22. 22.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) an input (c) a power source (d) an output
23. 23.⚡ Power tells us … (a) the length of a wire (b) energy used each second (c) the size of a cell (d) the colour of light
24. 24.True or false: to start a fan when hot, use a motion sensor. (a) True (b) False
25. 25.True or false: a circle with a cross is the symbol for a resistor. (a) False (b) True
26. 26.What does a thermistor do? (a) turns a fan or wheels (b) stores a little charge (c) beeps for an alarm (d) senses how hot it is
27. 27.🔢 To run one loop of a plant-watering program, which comes first: “switch the pump on/off” or “wait a few seconds”? (a) switch the pump on/off (b) wait a few seconds
28. 28.Which job needs an LED? (a) show a status light (b) spin a robot’s wheels (c) beep an alarm (d) turn to an exact angle
29. 29.🔍 An object is 340 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
30. 30.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) resistor (b) bulb (c) cell (d) capacitor
31. 31.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
32. 32.True or false: two equal parallel lines is the symbol for a capacitor. (a) True (b) False
33. 33.🧮 A 1 V battery is joined to 2 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
34. 34.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = V ÷ I (c) R = V × I (d) R = I ÷ V
35. 35.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) takes 1 away (c) adds 1 to count (d) prints 1
36. 36.True or false: to stop if a part gets hot is not safe. (a) True (b) False
37. 37.Which of these usually has a microcontroller inside? (a) a plain wall switch (b) a hand pump (c) a digital alarm clock (d) a wind-up toy
38. 38.🔍 Which sensor would you use to stop a robot near walls? (a) a distance sensor (b) a rain sensor (c) a light sensor (d) a motion sensor
39. 39.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) their sum (c) always zero (d) less than either one
40. 40.🔺 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

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