Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 847 · 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 1.5 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
2. 2.🌈 Which band is read first on a resistor? (a) any band (b) the widest gap (c) the gold band (d) the one nearest an end
3. 3.🌈 A resistor has the colour bands grey, blue, red. What is its value in kilo-ohms (kΩ)? =
4. 4.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) bulb (b) resistor (c) switch (d) cell
5. 5.⏱️ A program says “wait 6000 ms”. How many seconds is that? =
6. 6.🔢 To get a sensor reading onto a phone, what comes right after “it is sent by Wi-Fi”? (a) the sensor measures (b) the board reads it (c) the cloud stores it (d) the app shows it
7. 7.📏 How many milliamperes (mA) is 2.23 A?
8. 8.🔌 Which metal is used for most electric wires at home? (a) copper (b) plastic (c) glass (d) rubber
9. 9.True or false: to fly kites in open fields is safe. (a) False (b) True
10. 10.🔺 A 5 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
11. 11.Which drawing is the symbol for a switch? (a) a small empty box (b) a circle with M inside (c) a line lifted at a gap (d) one tall, one short bar
12. 12.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
13. 13.True or false: “a button press” is the process. (a) True (b) False
14. 14.⏱️ repeat 7 times { buzzer ON; wait 400 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
15. 15.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
16. 16.⚡ What does an electric kettle mainly change electricity into? (a) light (b) sound (c) heat (d) movement
17. 17.⚡ What does a tube light mainly change electricity into? (a) light (b) heat (c) movement (d) sound
18. 18.🔋 4 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)? =
19. 19.🔋 How many 1.5 V cells must be joined in series to give 6 V?
20. 20.🧮 A 2.4 V battery is joined to 6 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
21. 21.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) cell (b) resistor (c) junction (d) wire
22. 22.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
23. 23.🔺 A current of 20 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
24. 24.🔋 8 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
25. 25.🧩 Which component limits the current? (a) potentiometer (b) thermistor (c) resistor (d) LDR
26. 26.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
27. 27.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave fridge door open (c) leave the TV on standby (d) switch off empty rooms
28. 28.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) resistor (b) switch (c) cell (d) capacitor
29. 29.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
30. 30.⏱️ A program says “wait 2500 ms”. How many seconds is that? =
31. 31.What does the phone app do? (a) measures the real world (b) reads values, decides (c) shows data to you (d) stores data online
32. 32.True or false: on an LED, the shorter leg is the cathode (−). (a) True (b) False
33. 33.🔺 A current of 25 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
34. 34.Which of these mainly makes sound? (a) an electric iron (b) a mixer grinder (c) an electric toy car (d) a loudspeaker
35. 35.Which drawing is the symbol for a bulb? (a) a circle with an X in it (b) many long-short pairs (c) triangle, bar and arrows (d) two equal parallel lines
36. 36.True or false: the voltmeter measures voltage. (a) True (b) False
37. 37.⚡ What does a mixer grinder mainly change electricity into? (a) heat (b) movement (c) sound (d) light
38. 38.🗺️ In an input → process → output plan, is “a temperature reading” the input, the process or the output? (a) output (b) input (c) process
39. 39.🔁 x = 3
    repeat 5 times { x = x × 2 }
    What is x at the end?
40. 40.🔘 Which kind of switch stays where you flip it? (a) a slide switch (b) a toggle switch (c) a tilt switch (d) a push button

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