Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 383 · 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 of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) all wires are joined (d) a wire has come loose
2. 2.🤖 Does a wind-up toy usually have a microcontroller inside? (a) No (b) Yes
3. 3.🔺 A current of 20 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 1200 Ω resistor? (a) brown-red-red (b) red-brown-red (c) brown-red-orange (d) brown-red-brown
5. 5.🔌 Is a motor an input or an output for a microcontroller? (a) input (b) output
6. 6.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
7. 7.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it lights brighter (c) it does not light (d) it changes colour
8. 8.Which of these is an insulator? (a) a brass key (b) a safety pin (c) a wooden stick (d) aluminium foil
9. 9.🔘 A bulb and a cell are joined through 2 switches on 2 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
10. 10.🔁 count = 0
    repeat 9 times { count = count + 5 }
    What is count at the end?
11. 11.🔋 8 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
12. 12.🔍 A distance sensor sends a sound pulse and hears the echo 3 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
13. 13.🔁 repeat 2 times { repeat 6 times { beep } }
    How many beeps are there?
14. 14.⏱️ repeat 8 times { buzzer ON; wait 500 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
15. 15.🏠 Which is a smart-home example? (a) a printed map (b) a candle in a jar (c) a hand fan (d) lights on from an app
16. 16.🔺 A current of 50 mA flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.Which drawing is the symbol for an LED? (a) triangle, bar and arrows (b) many long-short pairs (c) two or more cell symbols (d) two equal parallel lines
18. 18.🔋 Does a cell give electricity or use electricity? (a) uses electricity (b) gives electricity
19. 19.Which of these is an input? (a) a turning knob (b) a servo motor (c) an LED (d) a small display
20. 20.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a plain wall switch (c) a Wi-Fi weather station (d) a Wi-Fi smart plug
21. 21.Which of these is true of a series circuit? (a) each gets the full volts (b) a break stops every bulb (c) many paths for current (d) one out, the rest glow
22. 22.Which drawing is the symbol for a junction? (a) a straight line (b) a dot where wires meet (c) a circle with A inside (d) triangle, bar and arrows
23. 23.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 44 °C. What is shown? (a) Hot (b) Warm (c) Cool
24. 24.🔍 Which is the odd one out? (a) a school bell (b) a doorbell (c) an electric kettle (d) a buzzer
25. 25.🌈 A resistor has the colour bands yellow, grey, red. What is its value (in ohms)?
26. 26.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
27. 27.🔺 A current of 1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
28. 28.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
29. 29.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
30. 30.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 50 ms }
    How many milliseconds does one blink (ON + OFF) take?
31. 31.🤖 How does a new program get onto a microcontroller board? (a) typed on the chip (b) uploaded over USB (c) sent by sound (d) drawn with a pen
32. 32.🔺 A current of 40 mA flows when 13.2 V is joined across a resistor. What is its resistance (in ohms)?
33. 33.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
34. 34.🔋 Does a solar panel give electricity or use electricity? (a) gives electricity (b) uses electricity
35. 35.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) not an IoT device (b) an IoT device
36. 36.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) stays the same (d) becomes zero
37. 37.💡 An LED is joined to a 6 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) lights up (b) does not light (c) may burn out
38. 38.True or false: a push button works only while pressed. (a) False (b) True
39. 39.🌈 A resistor has the colour bands violet, brown, brown. What is its value (in ohms)?
40. 40.🔋 What is a battery? (a) one single wire (b) a switch with a lid (c) a kind of bulb (d) two or more cells joined

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