Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 987 · 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) a kind of bulb (c) two or more cells joined (d) one single wire
2. 2.🔋 7 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
3. 3.🧮 Resistors of 10 Ω, 10 Ω and 330 Ω are joined in series. What is the total resistance (in ohms)?
4. 4.🔐 Is it a good or a risky habit to accept every permission? (a) good habit (b) risky habit
5. 5.🧩 Which component makes things spin? (a) thermistor (b) resistor (c) LED (d) motor
6. 6.🤖 if (light < 300) { lamp ON } else { lamp OFF }
   The light sensor reads 273. What happens? (a) lamp ON (b) lamp OFF
7. 7.True or false: “bulbs share the voltage” is true of a series circuit. (a) False (b) True
8. 8.True or false: a digital thermometer usually has a microcontroller inside. (a) False (b) True
9. 9.⏱️ loop forever { LED ON; wait 800 ms; LED OFF; wait 1200 ms }
   How many times does the LED blink in 10 seconds?
10. 10.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) switch (b) ammeter (c) battery (d) bulb
11. 11.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) the shorter line (c) both lines (d) neither line
12. 12.Which of these is safe? (a) use small battery cells (b) touch a fallen wire (c) use a cable with cuts (d) use mains for a project
13. 13.Which of these is true of a series circuit? (a) many paths for current (b) one out, the rest glow (c) a single current path (d) each gets the full volts
14. 14.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel coin across the gap. Does the bulb glow? (a) No (b) Yes
15. 15.🔍 Which is the odd one out? (a) a room heater (b) a rice cooker (c) a doorbell (d) a toaster
16. 16.🔍 A distance sensor sends a sound pulse and hears the echo 14 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
17. 17.True or false: to fly kites in open fields is safe. (a) False (b) True
18. 18.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
19. 19.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 60 (d) 10
20. 20.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) only one (c) none (d) both of them
21. 21.True or false: a safety pin is a conductor. (a) False (b) True
22. 22.True or false: a night lamp mainly gives out light. (a) False (b) True
23. 23.Which of these is an insulator? (a) a rubber eraser (b) an iron nail (c) a graphite rod (d) a safety pin
24. 24.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
26. 26.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a brass key across the gap. Does the bulb glow? (a) No (b) Yes
27. 27.🧮 A 2 V battery is joined to 8 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
28. 28.True or false: to read app permissions is a risky habit. (a) True (b) False
29. 29.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) post it online (b) ask a parent first (c) share it with friends (d) type it all in
30. 30.True or false: “check if temp > 30” is the input. (a) True (b) False
31. 31.💡 An LED is joined to a 5 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) may burn out (c) lights up
32. 32.🔁 count = 5
    while (count < 33) { count = count + 4 }
    How many times does the loop run?
33. 33.💡 A red LED uses 2 V and should get 10 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
34. 34.🔁 total = 0
    for i = 1 to 9 { total = total + i }
    What is total at the end?
35. 35.🔍 Which is the odd one out? (a) a ceramic cup (b) a plastic straw (c) a wooden stick (d) a graphite rod
36. 36.⏱️ A program says “wait 9750 ms”. How many seconds is that? =
37. 37.⚡ Which formula gives electric power? (a) P = V × I (b) P = V + I (c) P = I ÷ V (d) P = V ÷ I
38. 38.📶 Digital or analog: HIGH or LOW only? (a) analog (b) digital
39. 39.🔢 To plan an electronics project, what comes right after “pick a problem to solve”? (a) list inputs and outputs (b) test it and fix it (c) draw the circuit diagram (d) build it with an adult
40. 40.True or false: “each gets the full volts” is true of a parallel circuit. (a) False (b) True

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