Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 640 · 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 0.75 W device works on 1.5 V. What current does it take (in amperes)? =
2. 2.🔋 Does a water pump give electricity or use electricity? (a) uses electricity (b) gives electricity
3. 3.⚡ Which formula gives electric power? (a) P = V × I (b) P = I ÷ V (c) P = V + I (d) P = V ÷ I
4. 4.🔘 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) Yes (b) No
5. 5.💡 An LED is joined to a 5 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) lights up (b) may burn out (c) does not light
6. 6.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the one nearest an end (d) the widest gap
7. 7.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 50 % (c) 0 % (d) 25 %
8. 8.🔋 6 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
9. 9.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = I ÷ V (c) R = V ÷ I (d) R = V + I
10. 10.True or false: a reed switch closes near a magnet. (a) True (b) False
11. 11.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a graphite rod across the gap. Does the bulb glow? (a) No (b) Yes
12. 12.🔘 When a switch is ON, the circuit is … (a) broken (b) open (c) closed (d) cut
13. 13.⏱️ How many milliseconds is a wait of 1.4 seconds?
14. 14.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
15. 15.Which of these is an input? (a) a motor (b) a water pump (c) a temperature sensor (d) a buzzer
16. 16.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) dotted circles (c) little stars (d) wavy lines
17. 17.🔍 Which is the odd one out? (a) a table fan (b) a tube light (c) a ceiling fan (d) an exhaust fan
18. 18.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 45 %. What happens? (a) pump OFF (b) pump ON
19. 19.📶 Digital or analog: the room temperature? (a) digital (b) analog
20. 20.🤖 Does a TV remote usually have a microcontroller inside? (a) No (b) Yes
21. 21.Which job is done by the reset button? (a) keeps the voltage steady (b) shows the board is on (c) restarts the program (d) runs the program
22. 22.🤖 Does a digital alarm clock usually have a microcontroller inside? (a) Yes (b) No
23. 23.What does a toggle switch do? (a) works only while pressed (b) springs back when let go (c) slides side to side (d) stays where you flip it
24. 24.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
25. 25.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
26. 26.💡 Why does an LED need a resistor in series? (a) to store charge (b) to change its colour (c) to make it brighter (d) to limit the current
27. 27.🔁 count = 8
    repeat 10 times { count = count + 5 }
    What is count at the end?
28. 28.Which drawing is the symbol for a bulb? (a) a circle with a cross (b) a small empty box (c) one tall, one short bar (d) a straight line
29. 29.What does a buzzer do? (a) blows if current is high (b) glows using little power (c) limits the current (d) makes a beeping sound
30. 30.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 3 seconds?
31. 31.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
32. 32.💡 5 identical bulbs are joined in series with a 15 V battery (ideal wires). How many volts does each bulb get? =
33. 33.⚡ Power tells us … (a) the size of a cell (b) the colour of light (c) the length of a wire (d) energy used each second
34. 34.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is OFF, B is ON, C is OFF and D is OFF. Does the bulb glow? (a) No (b) Yes
35. 35.🌐 In an IoT system, which part reads values, decides? (a) sensor (b) phone app (c) cloud server (d) microcontroller
36. 36.✏️ In a circuit diagram, which part is drawn as a straight line? (a) bulb (b) wire (c) cell (d) resistor
37. 37.🔺 A current of 1.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
38. 38.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 610 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
39. 39.Which of these is true of a series circuit? (a) a break stops every bulb (b) one out, the rest glow (c) many paths for current (d) used in house wiring
40. 40.💡 4 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?

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