Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 743 · 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.⚠️ About how many volts do home sockets in India supply? (a) 12 V (b) 9 V (c) 1.5 V (d) 230 V
2. 2.🔍 Which is the odd one out? (a) a motion sensor (b) a light sensor (c) a buzzer (d) a turning knob
3. 3.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) neither line (c) the longer line (d) the shorter line
4. 4.📏 How many kilo-ohms (kΩ) is 6200 Ω? =
5. 5.🔌 Which metal is used for most electric wires at home? (a) plastic (b) glass (c) rubber (d) copper
6. 6.True or false: “a tilt switch: on or off” is an analog signal. (a) True (b) False
7. 7.⚡ A device works on 9 V and takes 2 A. What is its power (in watts)? =
8. 8.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
9. 9.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire has come loose (d) all wires are joined
10. 10.True or false: to switch off empty rooms saves electricity. (a) True (b) False
11. 11.💡 In a series circuit, how many paths does the current have? (a) one (b) two (c) one for each bulb (d) none
12. 12.🔁 count = 2
    while (count < 10) { count = count + 4 }
    How many times does the loop run?
13. 13.📏 Which unit measures current? (a) watt (W) (b) ohm (Ω) (c) volt (V) (d) ampere (A)
14. 14.🔍 Which is the odd one out? (a) a plastic straw (b) a woollen thread (c) a dry cork (d) a metal paper clip
15. 15.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 5 V supply. What current flows (in mA)?
16. 16.🔺 A current of 0.1 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
18. 18.🔁 count = 6
    repeat 8 times { count = count + 3 }
    What is count at the end?
19. 19.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by a plastic straw. Does the bulb glow? (a) No (b) Yes
20. 20.Which of these usually has a microcontroller inside? (a) a wind-up toy (b) a hand pump (c) a candle (d) a TV remote
21. 21.🔋 What should you do with used-up cells? (a) bury them in soil (b) throw them in a fire (c) cut them open (d) give them for recycling
22. 22.🗺️ Before building a project, what should you write down first? (a) the final price (b) nothing at all (c) inputs and outputs (d) the box colour
23. 23.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
24. 24.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the power LED (b) the voltage regulator (c) the pins (d) the main chip
25. 25.🧩 Which component limits the current? (a) potentiometer (b) transistor (c) resistor (d) capacitor
26. 26.⚡ A device works on 5 V and takes 0.25 A. What is its power (in watts)? =
27. 27.⚠️ Is it safe to keep drinks far away? (a) not safe (b) safe
28. 28.🔺 A 10 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
29. 29.Which of these is not safe? (a) build with an adult near (b) stay away from pylons (c) fly kites in open fields (d) poke things in a socket
30. 30.💡 A battery lights 5 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
31. 31.💡 An LED is joined to a 3 V battery through a 470 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) does not light (b) lights up (c) may burn out
32. 32.⚡ A 12 W device works on 6 V. What current does it take (in amperes)? =
33. 33.📶 Digital or analog: many values in a range? (a) digital (b) analog
34. 34.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) diode (b) cell (c) battery (d) wire
35. 35.⚡ A 10 W device works on 5 V. What current does it take (in amperes)? =
36. 36.💡 Why does an LED need a resistor in series? (a) to store charge (b) to make it brighter (c) to limit the current (d) to change its colour
37. 37.⚠️ Which power source should children use for electronics projects? (a) a mains extension board (b) a small battery pack (c) an inverter socket (d) a wall socket
38. 38.🔁 x = 1
    repeat 1 time { x = x × 2 }
    What is x at the end?
39. 39.🔐 Is it a good or a risky habit to cover unused cameras? (a) good habit (b) risky habit
40. 40.🔍 Which is the odd one out? (a) a motion sensor signal (b) decide if soil is dry (c) a temperature reading (d) a button press

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