Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 677 · 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.True or false: to set up with a parent is a risky habit. (a) True (b) False
2. 2.🌈 A resistor has the colour bands green, white, red. What is its value in kilo-ohms (kΩ)? =
3. 3.🔗 Series or parallel circuit: “used in house wiring”? (a) series (b) parallel
4. 4.🔐 Is it a good or a risky habit to share camera links? (a) risky habit (b) good habit
5. 5.⚡ What does a loudspeaker mainly change electricity into? (a) heat (b) light (c) movement (d) sound
6. 6.True or false: a buzzer makes a beeping sound. (a) True (b) False
7. 7.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
8. 8.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
   The temperature is 20 °C. What is shown? (a) Cool (b) Hot (c) Warm
9. 9.🌈 In the resistor colour code, which number does violet stand for?
10. 10.📏 Which unit measures energy used each second? (a) watt (W) (b) volt (V) (c) ampere (A) (d) ohm (Ω)
11. 11.Which of these is true of a parallel circuit? (a) own switch for each bulb (b) a break stops every bulb (c) bulbs share the voltage (d) one bulb out, all go out
12. 12.True or false: a hand pump usually has a microcontroller inside. (a) True (b) False
13. 13.True or false: a potentiometer senses how hot it is. (a) False (b) True
14. 14.True or false: to leave fridge door open wastes electricity. (a) False (b) True
15. 15.🌐 What does IoT stand for? (a) Internet of Talk (b) Input of Tools (c) Inside of Toys (d) Internet of Things
16. 16.🔋 3 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
17. 17.🔍 A distance sensor sends a sound pulse and hears the echo 16 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
18. 18.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
19. 19.🔁 x = 4
    repeat 1 time { x = x × 2 }
    What is x at the end?
20. 20.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
21. 21.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
22. 22.💡 2 identical bulbs are in parallel and each one takes 1 A. What total current (in amperes) comes from the battery? =
23. 23.🔺 A current of 0.2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
24. 24.Which of these is an input? (a) a push button (b) an LED (c) a speaker (d) a servo motor
25. 25.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
26. 26.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 57 Ω resistor? (a) green-violet-black (b) green-violet-brown (c) violet-green-black (d) blue-violet-black
27. 27.🧩 Which component smooths a wobbly supply? (a) thermistor (b) buzzer (c) capacitor (d) resistor
28. 28.⚠️ Is it safe to build with an adult near? (a) safe (b) not safe
29. 29.Which of these wastes electricity? (a) switch off empty rooms (b) leave the TV on standby (c) unplug idle chargers (d) close the fridge quickly
30. 30.🔺 A current of 1.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
31. 31.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
32. 32.🌐 Is a battery torch an IoT device? (a) not an IoT device (b) an IoT device
33. 33.⚡ 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
34. 34.🔍 Which is the odd one out? (a) an exhaust fan (b) a night lamp (c) a mixer grinder (d) a table fan
35. 35.🔺 A 23.5 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
36. 36.True or false: a circle with an X in it is the symbol for a bulb. (a) True (b) False
37. 37.🧮 Five equal 125 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
38. 38.🌈 A resistor has the colour bands brown, violet, black. What is its value (in ohms)?
39. 39.⚡ A 1.5 W device works on 3 V. What current does it take (in amperes)? =
40. 40.🔺 A 1.6 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =

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