Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 285 · 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 68 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
2. 2.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a safe circuit (b) an open circuit (c) a parallel circuit (d) a short circuit
3. 3.🔁 repeat 5 times { repeat 3 times { beep } }
   How many beeps are there?
4. 4.📏 How many amperes (A) is 2320 mA? =
5. 5.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 650 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
6. 6.Which drawing is the symbol for a resistor? (a) a circle with A inside (b) a plain rectangle (c) triangle, bar and arrows (d) many long-short pairs
7. 7.🔋 What is a battery? (a) a kind of bulb (b) one single wire (c) two or more cells joined (d) a switch with a lid
8. 8.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 7000 Ω resistor? (a) violet-black-orange (b) violet-black-brown (c) grey-violet-red (d) violet-black-red
9. 9.⚡ A device works on 5 V and takes 0.2 A. What is its power (in watts)? =
10. 10.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the process (c) the input (d) the battery
11. 11.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 ampere
12. 12.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
13. 13.⚡ A 2.5 W device works on 5 V. What current does it take (in amperes)? =
14. 14.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    set pin 7 LOW
    set pin 8 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
15. 15.🔋 How many 1.5 V cells must be joined in series to give 7.5 V?
16. 16.What does a toggle switch do? (a) closes near a magnet (b) works only while pressed (c) slides side to side (d) flips up or down
17. 17.🔍 Which is the odd one out? (a) a keypad (b) a turning knob (c) a small display (d) a motion sensor
18. 18.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) symbols are heavier (c) quick and clear for all (d) to make it colourful
19. 19.🔘 Which kind of switch stays where you flip it? (a) a reed switch (b) a tilt switch (c) a toggle switch (d) a push button
20. 20.🔺 A current of 0.25 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
21. 21.🔋 Does a generator give electricity or use electricity? (a) uses electricity (b) gives electricity
22. 22.🤖 “if (A AND B)” is true when … (a) both are false (b) both A and B are true (c) only A is true (d) only B is true
23. 23.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
24. 24.Which job is done by the pins? (a) shows the board is on (b) restarts the program (c) runs the program (d) connect sensors and LEDs
25. 25.🔍 Which is the odd one out? (a) a plain table fan (b) a fitness band with app (c) an app-controlled bulb (d) a smart energy meter
26. 26.Which of these is true of a series circuit? (a) many paths for current (b) one out, the rest glow (c) one bulb out, all go out (d) each gets the full volts
27. 27.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 17 %. What happens? (a) pump ON (b) pump OFF
28. 28.🔁 What does a variable do in a program? (a) joins two wires (b) stores a value (c) blinks an LED (d) measures light
29. 29.💡 Why is house wiring done in parallel? (a) so all go off together (b) to make bulbs dim (c) to save copper only (d) each gets full voltage
30. 30.⚡ Which tiny particles drift along a metal wire to carry the current? (a) dust particles (b) electrons (c) photons (d) water drops
31. 31.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 300 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
32. 32.Which of these is safe? (a) touch a switch when wet (b) touch a fallen wire (c) fly kites in open fields (d) climb an electric pole
33. 33.Which of these mainly makes sound? (a) a mixer grinder (b) a tube light (c) an electric drill (d) a doorbell
34. 34.🔺 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
35. 35.🔺 A current of 0.2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
36. 36.⚡ A device works on 6 V and takes 0.25 A. What is its power (in watts)? =
37. 37.🔍 Which is the odd one out? (a) a glass marble (b) a safety pin (c) a steel spoon (d) a steel coin
38. 38.🔘 When a switch is ON, the circuit is … (a) open (b) broken (c) cut (d) closed
39. 39.🔺 A current of 0.25 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
40. 40.🌈 In the resistor colour code, which number does orange stand for?

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