Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 741 · 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.🔁 count = 3
   repeat 5 times { count = count + 5 }
   What is count at the end?
2. 2.🧮 A 1.4 V battery is joined to 5 Ω and 2 Ω resistors in series. What current flows (in amperes)? =
3. 3.Which drawing is the symbol for a capacitor? (a) two equal parallel lines (b) a plain rectangle (c) a circle with an X in it (d) a straight line
4. 4.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
5. 5.💡 5 identical bulbs are joined in series with a 15 V battery (ideal wires). How many volts does each bulb get? =
6. 6.Which of these is not safe? (a) dry your hands first (b) use a cable with cuts (c) use small battery cells (d) stop if a part gets hot
7. 7.🔁 total = 0
   for i = 1 to 9 { total = total + i }
   What is total at the end?
8. 8.What does a resistor do? (a) senses how hot it is (b) glows using little power (c) beeps for an alarm (d) limits the current
9. 9.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False
10. 10.⚡ What does a night lamp mainly change electricity into? (a) heat (b) sound (c) light (d) movement
11. 11.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) smaller (c) stay the same (d) zero
12. 12.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) output (b) input (c) process
13. 13.Which job needs a motion sensor? (a) keep an incubator warm (b) open blinds at sunrise (c) spot someone walking in (d) water a dry plant
14. 14.📏 Which unit measures current? (a) volt (V) (b) watt (W) (c) ohm (Ω) (d) ampere (A)
15. 15.🔁 What does a variable do in a program? (a) stores a value (b) blinks an LED (c) joins two wires (d) measures light
16. 16.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 27 °C. What is shown? (a) Cool (b) Warm (c) Hot
17. 17.Which of these is an insulator? (a) a steel spoon (b) aluminium foil (c) a steel coin (d) a wooden stick
18. 18.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the shorter line (c) both lines (d) the longer line
19. 19.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) little stars (c) wavy lines (d) dotted circles
20. 20.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is ON, C is ON and D is OFF. Does the bulb glow? (a) No (b) Yes
21. 21.✏️ In a circuit diagram, which part is drawn as a circle with M inside? (a) voltmeter (b) switch (c) cell (d) motor
22. 22.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
23. 23.🔺 A 2.2 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?
24. 24.🔋 4 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
25. 25.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a capacitor (c) a resistor (d) a diode
26. 26.What does the cloud server do? (a) carries the data (b) measures the real world (c) stores data online (d) acts on a command
27. 27.True or false: the push of a cell is measured in amperes (A). (a) False (b) True
28. 28.🔍 Which is the odd one out? (a) a buzzer (b) a servo motor (c) a light sensor (d) a speaker
29. 29.🔘 When a switch is ON, the circuit is … (a) open (b) cut (c) closed (d) broken
30. 30.🔺 A 0.4 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
31. 31.🔍 Which is the odd one out? (a) throw cells in a fire (b) stay away from pylons (c) dry your hands first (d) fly kites in open fields
32. 32.Which of these is a conductor? (a) a ceramic cup (b) a plastic ruler (c) a metal paper clip (d) a rubber eraser
33. 33.Which of these wastes electricity? (a) use daylight to read (b) use LED lamps (c) unplug idle chargers (d) leave fridge door open
34. 34.🌐 A weather station sends one reading every 20 seconds. How many readings does it send in 10 minutes?
35. 35.🔍 Which sensor would you use to stop a robot near walls? (a) a sound sensor (b) a temperature sensor (c) a gas sensor (d) a distance sensor
36. 36.🔋 7 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
37. 37.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
38. 38.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
39. 39.True or false: a loudspeaker mainly gives out light. (a) True (b) False
40. 40.True or false: a buzzer makes a beeping sound. (a) False (b) True

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