Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 753 · 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.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) bulb (b) battery (c) cell (d) resistor
2. 2.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
3. 3.🔁 count = 0
   repeat 8 times { count = count + 10 }
   What is count at the end?
4. 4.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) so all go off together (c) each gets full voltage (d) to save copper only
5. 5.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a safe circuit (b) a parallel circuit (c) a short circuit (d) an open circuit
6. 6.🧮 Resistors of 10 Ω, 47 Ω, 330 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
7. 7.🔌 Is a turning knob an input or an output for a microcontroller? (a) output (b) input
8. 8.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) pauses for half a second (c) turns the LED off (d) blinks 500 times
9. 9.🔋 6 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
10. 10.🤖 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
11. 11.🔍 Which is the odd one out? (a) a dry cork (b) a brass key (c) a paper strip (d) a wooden stick
12. 12.🔺 A 4.5 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
13. 13.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
14. 14.🔢 To get a sensor reading onto a phone, which comes first: “the sensor measures” or “the board reads it”? (a) the sensor measures (b) the board reads it
15. 15.🔺 A 0.4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
16. 16.Which drawing is the symbol for a capacitor? (a) a circle with A inside (b) a long and a short line (c) triangle, bar and arrows (d) two equal parallel lines
17. 17.📏 In the water-pipe picture of a circuit, current is like … (a) the pipe colour (b) a narrow pipe (c) the water pressure (d) the flow of water
18. 18.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) a smart energy meter (c) a Wi-Fi weather station (d) a pencil sharpener
19. 19.🔍 A distance sensor sends a sound pulse and hears the echo 13 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
20. 20.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
21. 21.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
22. 22.💡 An LED is joined to a 3 V battery through a 470 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) lights up (c) does not light
23. 23.🔍 Which is the odd one out? (a) a Wi-Fi weather station (b) a smart energy meter (c) a plain table fan (d) an app-controlled bulb
24. 24.🔋 What is a battery? (a) two or more cells joined (b) a switch with a lid (c) one single wire (d) a kind of bulb
25. 25.🔘 Which kind of switch closes near a magnet? (a) a push button (b) a toggle switch (c) a reed switch (d) a tilt switch
26. 26.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is ON. Does the bulb glow? (a) No (b) Yes
27. 27.🔘 Which kind of switch closes when tipped over? (a) a tilt switch (b) a push button (c) a slide switch (d) a toggle switch
28. 28.🔍 A distance sensor sends a sound pulse and hears the echo 12 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
29. 29.What does a potentiometer do? (a) turns a fan or wheels (b) has coloured bands (c) is a resistance knob (d) boosts a small signal
30. 30.🔍 Which is the odd one out? (a) a copper wire (b) a steel spoon (c) a rubber band (d) aluminium foil
31. 31.Which of these wastes electricity? (a) run fans in empty rooms (b) use daylight to read (c) unplug idle chargers (d) set the AC to 24 °C
32. 32.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V × R (c) I = V + R (d) I = V ÷ R
33. 33.True or false: an electric toy car mainly makes sound. (a) False (b) True
34. 34.Which of these is an IoT device? (a) a Wi-Fi weather station (b) a plain table fan (c) a pencil sharpener (d) a wind-up clock
35. 35.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
36. 36.🔺 A current of 0.2 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
37. 37.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V + I (c) P = V × I (d) P = V ÷ I
38. 38.⚡ A device works on 5 V and takes 2 A. What is its power (in watts)? =
39. 39.⏱️ repeat 5 times { buzzer ON; wait 900 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
40. 40.True or false: a dot where wires meet is the symbol for a junction. (a) False (b) True

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