Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 219 · 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 kind of switch flips up or down? (a) a tilt switch (b) a reed switch (c) a push button (d) a toggle switch
2. 2.🔍 Which is the odd one out? (a) a fitness band with app (b) a plain wall switch (c) a wind-up clock (d) a paper calendar
3. 3.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
4. 4.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they get dimmer (c) they keep glowing (d) they all go out
5. 5.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
6. 6.⚡ A 1.25 W device works on 5 V. What current does it take (in amperes)? =
7. 7.🤖 Microcontroller or laptop: which one runs one small program? (a) laptop (b) microcontroller
8. 8.🧩 Which component smooths a wobbly supply? (a) diode (b) potentiometer (c) LDR (d) capacitor
9. 9.📏 How many ohms (Ω) is 2.8 kΩ?
10. 10.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
11. 11.🔋 What should you do with used-up cells? (a) throw them in a fire (b) bury them in soil (c) give them for recycling (d) cut them open
12. 12.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 88 Ω resistor? (a) grey-white-black (b) grey-grey-black (c) grey-grey-brown (d) white-grey-black
13. 13.Which drawing is the symbol for a cell? (a) a straight line (b) a long and a short line (c) a circle with M inside (d) triangle against a bar
14. 14.⚡ What does a toaster mainly change electricity into? (a) light (b) heat (c) sound (d) movement
15. 15.💡 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) the same (c) brighter
16. 16.🔍 Which is the odd one out? (a) a push button (b) a sound sensor (c) an LED (d) a keypad
17. 17.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) not an IoT device (b) an IoT device
18. 18.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I × R (c) V = I + R (d) V = R ÷ I
19. 19.🔘 Which kind of switch closes when tipped over? (a) a reed switch (b) a tilt switch (c) a push button (d) a toggle switch
20. 20.🧩 Which component boosts a small signal? (a) potentiometer (b) motor (c) LED (d) transistor
21. 21.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
22. 22.🔺 A current of 25 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🗺️ Before building a project, what should you write down first? (a) the final price (b) nothing at all (c) inputs and outputs (d) the box colour
24. 24.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = R ÷ V (d) I = V × R
25. 25.🔍 Which sensor would you use to stop a robot near walls? (a) a rain sensor (b) a light sensor (c) a distance sensor (d) a sound sensor
26. 26.🔺 A current of 0.1 A flows when 0.5 V is joined across a resistor. What is its resistance (in ohms)?
27. 27.What does a thermistor do? (a) beeps for an alarm (b) turns a fan or wheels (c) senses how bright it is (d) senses how hot it is
28. 28.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 20 readings take?
29. 29.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) energy used each second (d) the colour of light
30. 30.True or false: the voltmeter measures voltage. (a) True (b) False
31. 31.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
32. 32.📏 Which unit measures energy used each second? (a) ohm (Ω) (b) volt (V) (c) ampere (A) (d) watt (W)
33. 33.⚠️ Is it safe to stop if a part gets hot? (a) not safe (b) safe
34. 34.Which of these is the process? (a) a temperature reading (b) a light level reading (c) the pump turns on (d) count button presses
35. 35.🔋 4 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
36. 36.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
37. 37.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) ammeter (b) battery (c) motor (d) LED
38. 38.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
39. 39.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 17 Ω resistor? (a) brown-violet-brown (b) red-violet-black (c) brown-violet-black (d) violet-brown-black
40. 40.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =

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