Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 683 · 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.🔋 How many volts does one ordinary torch cell give? (a) 0.5 V (b) 15 V (c) 1.5 V (d) 230 V
2. 2.🧮 Four equal 80 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
4. 4.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) False (b) True
5. 5.Which job is done by the power LED? (a) shows the board is on (b) connect sensors and LEDs (c) runs the program (d) restarts the program
6. 6.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the battery (c) the process (d) the input
7. 7.Which of these is measured in ohms (Ω)? (a) voltage (b) current (c) resistance (d) the flow of charge
8. 8.🤖 What is a microcontroller? (a) a kind of bulb (b) a computer on one chip (c) a big desktop computer (d) a type of battery
9. 9.🔁 count = 8
   repeat 2 times { count = count + 3 }
   What is count at the end?
10. 10.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) stays the same (d) gets smaller
11. 11.⚠️ Is it safe to touch a fallen wire? (a) not safe (b) safe
12. 12.🧩 Which component beeps for an alarm? (a) thermistor (b) LDR (c) buzzer (d) LED
13. 13.🔍 Which is the odd one out? (a) open a phone charger (b) use mains for a project (c) build with an adult near (d) climb an electric pole
14. 14.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 25 % (c) 0 % (d) 5 %
15. 15.🔋 How many 2 V cells must be joined in series to give 12 V?
16. 16.🔋 What is a battery? (a) a kind of bulb (b) two or more cells joined (c) one single wire (d) a switch with a lid
17. 17.True or false: a long and a short line is the symbol for a cell. (a) False (b) True
18. 18.True or false: an electric kettle mainly makes movement. (a) False (b) True
19. 19.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = R ÷ V (d) I = V × R
20. 20.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. Does bulb 1 glow? (a) No (b) Yes
21. 21.🔺 A current of 20 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
22. 22.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
23. 23.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) a single current path (c) bulbs share the voltage (d) one out, the rest glow
24. 24.🔺 A current of 0.25 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
25. 25.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 540 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
26. 26.💡 4 identical bulbs are joined in series with a 4 V battery (ideal wires). How many volts does each bulb get? =
27. 27.Which drawing is the symbol for a voltmeter? (a) a straight line (b) a circle with V inside (c) two equal parallel lines (d) many long-short pairs
28. 28.💡 6 identical bulbs are in parallel and each bulb has its own switch on its path. 4 of the switches are OFF and the rest are ON. How many bulbs glow?
29. 29.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) in series (d) not joined
30. 30.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
31. 31.🧩 Which component glows using little power? (a) LED (b) thermistor (c) diode (d) fuse
32. 32.🔢 To plan an electronics project, which is the LAST step? (a) list inputs and outputs (b) draw the circuit diagram (c) test it and fix it (d) build it with an adult
33. 33.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) voltmeter (b) cell (c) junction (d) capacitor
34. 34.🔐 Which is the strongest password for a home smart camera? (a) 123456 (b) Tiger#Lamp42!Moon (c) password (d) admin
35. 35.📏 Which unit measures how much a part resists? (a) watt (W) (b) ampere (A) (c) volt (V) (d) ohm (Ω)
36. 36.True or false: a straight line is the symbol for a switch. (a) True (b) False
37. 37.💡 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?
38. 38.💡 What does LED stand for? (a) low energy device (b) light-emitting diode (c) light energy dial (d) large electric dial
39. 39.⚠️ Is it safe to use a cable with cuts? (a) safe (b) not safe
40. 40.🧮 Resistors of 33 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?

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