Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 957 · 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 drawing is the symbol for a diode? (a) a circle with A inside (b) triangle against a bar (c) a circle with V inside (d) two or more cell symbols
2. 2.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
3. 3.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the bulb is unscrewed
4. 4.Which of these is the output? (a) a motion sensor signal (b) an alert on the phone (c) decide if soil is dry (d) a light level reading
5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the switch is OFF (c) the switch is ON (d) the loop is complete
6. 6.🔁 count = 1
   while (count < 9) { count = count + 2 }
   How many times does the loop run?
7. 7.What does a toggle switch do? (a) slides side to side (b) stays where you flip it (c) springs back when let go (d) works only while pressed
8. 8.🔐 Is it a good or a risky habit to turn off unused gadgets? (a) good habit (b) risky habit
9. 9.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) chemical energy (b) movement energy (c) sound energy (d) light energy
10. 10.Which drawing is the symbol for a cell? (a) a circle with a cross (b) triangle against a bar (c) a long and a short line (d) a circle with M inside
11. 11.📏 Which unit measures resistance? (a) volt (V) (b) ampere (A) (c) watt (W) (d) ohm (Ω)
12. 12.🧮 Five equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
13. 13.🔺 A current of 2 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
14. 14.📏 How many kilowatts (kW) is 2000 W? =
15. 15.Which of these uses electricity? (a) a television (b) a cell (c) a solar panel (d) a battery
16. 16.⚡ What does a siren mainly change electricity into? (a) heat (b) movement (c) light (d) sound
17. 17.🔺 A 12 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
18. 18.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
19. 19.⚡ A device works on 1.5 V and takes 0.2 A. What is its power (in watts)? =
20. 20.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
21. 21.📏 Which unit measures the flow of charge? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
22. 22.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
23. 23.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) a fitness band with app (c) a smart energy meter (d) a wind-up clock
24. 24.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) False (b) True
25. 25.What does a diode do? (a) senses how bright it is (b) makes a beeping sound (c) lets current go one way (d) blows if current is high
26. 26.🌈 A resistor has the colour bands grey, grey, red. What is its value in kilo-ohms (kΩ)? =
27. 27.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is ON, C is ON and D is OFF. Does the bulb glow? (a) Yes (b) No
28. 28.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
29. 29.Which job needs a buzzer? (a) spin a robot’s wheels (b) beep an alarm (c) show the temperature (d) move water to plants
30. 30.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
31. 31.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
32. 32.🔍 Which sensor would you use to warn of a gas leak? (a) a temperature sensor (b) a gas sensor (c) a distance sensor (d) a motion sensor
33. 33.📶 A pin set LOW gives about … (a) 0 V (b) 5 V (c) 1.5 V (d) 9 V
34. 34.🔺 A 4.5 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
35. 35.What does a reed switch do? (a) springs back when let go (b) flips up or down (c) closes near a magnet (d) closes when tipped over
36. 36.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 250 Ω resistor? (a) red-green-brown (b) red-green-red (c) green-red-brown (d) red-green-black
37. 37.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 40 Ω resistor? (a) yellow-black-brown (b) yellow-black-black (c) green-yellow-black (d) green-black-black
38. 38.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 31 °C. What is shown? (a) Hot (b) Cool (c) Warm
39. 39.🔢 To plan an electronics project, which is the FIRST step? (a) test it and fix it (b) pick a problem to solve (c) build it with an adult (d) draw the circuit diagram
40. 40.🌈 A resistor has the colour bands red, blue, red. What is its value in kilo-ohms (kΩ)? =

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