Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 902 · 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.🔋 What is a battery? (a) a switch with a lid (b) two or more cells joined (c) a kind of bulb (d) one single wire
2. 2.🔁 count = 4
   while (count < 28) { count = count + 3 }
   How many times does the loop run?
3. 3.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) process (b) input (c) output
4. 4.🧮 Two resistors in parallel give a total that is … (a) always zero (b) less than either one (c) their sum (d) more than either one
5. 5.🔁 x = 3
   repeat 1 time { x = x × 2 }
   What is x at the end?
6. 6.Which of these is measured in volts (V)? (a) the push of a cell (b) power (c) energy used each second (d) resistance
7. 7.🔐 Which is the strongest password for a home smart camera? (a) 123456 (b) Tiger#Lamp42!Moon (c) admin (d) password
8. 8.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 7 LOW
   set pin 8 HIGH
   set pin 7 HIGH
   set pin 7 HIGH
   set pin 8 HIGH
   Is the LED ON or OFF at the end? (a) ON (b) OFF
9. 9.📏 Which unit measures the push of a cell? (a) watt (W) (b) ohm (Ω) (c) ampere (A) (d) volt (V)
10. 10.🔺 A 10 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
11. 11.🔍 Which is the odd one out? (a) a school bell (b) a tube light (c) an LED lamp (d) a street light
12. 12.🔁 total = 0
    for i = 1 to 3 { total = total + i }
    What is total at the end?
13. 13.Which job is done by the reset button? (a) connect sensors and LEDs (b) restarts the program (c) runs the program (d) keeps the voltage steady
14. 14.🔍 Which is the odd one out? (a) a fitness band with app (b) a plain table fan (c) a battery torch (d) a wind-up clock
15. 15.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
16. 16.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 10 (c) 1000 (d) 60
17. 17.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
18. 18.🔺 A current of 0.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
19. 19.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
20. 20.💡 An LED is joined to a 3 V battery through a 220 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) does not light (c) lights up
21. 21.⚡ A device works on 6 V and takes 0.5 A. What is its power (in watts)? =
22. 22.📏 In the water-pipe picture of a circuit, current is like … (a) a narrow pipe (b) the pipe colour (c) the flow of water (d) the water pressure
23. 23.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
24. 24.True or false: to use old filament bulbs saves electricity. (a) True (b) False
25. 25.💡 4 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
26. 26.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 300 ms }
    How many milliseconds does one blink (ON + OFF) take?
27. 27.Which of these is a conductor? (a) a plastic straw (b) a cotton thread (c) a ceramic cup (d) a brass key
28. 28.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when both are ON (c) when both are OFF (d) when either is ON
29. 29.Which of these is safe? (a) poke things in a socket (b) climb an electric pole (c) use a cable with cuts (d) fly kites in open fields
30. 30.🔺 A 5 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
31. 31.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the longer line (c) neither line (d) the shorter line
32. 32.True or false: a fuse blows if current is high. (a) True (b) False
33. 33.🔺 A current of 40 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
34. 34.💡 2 identical bulbs are in parallel and each one takes 0.25 A. What total current (in amperes) comes from the battery? =
35. 35.📏 How many ohms (Ω) is 5.8 kΩ?
36. 36.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) bulb (b) capacitor (c) wire (d) battery
37. 37.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
38. 38.True or false: “a soil moisture reading” is the process. (a) True (b) False
39. 39.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I × R (d) V = I + R
40. 40.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
    The temperature is 36 °C. What is shown? (a) Warm (b) Hot (c) Cool

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