Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 717 · 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.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) movement energy (b) sound energy (c) chemical energy (d) light energy
2. 2.🔺 A current of 2.5 A flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
3. 3.True or false: to set up with a parent is a good habit. (a) False (b) True
4. 4.Which drawing is the symbol for an LED? (a) a circle with V inside (b) triangle, bar and arrows (c) a plain rectangle (d) a circle with an X in it
5. 5.🌈 In the resistor colour code, which number does blue stand for?
6. 6.🧩 Which component stores a little charge? (a) fuse (b) capacitor (c) LDR (d) diode
7. 7.⏱️ repeat 3 times { buzzer ON; wait 700 ms; buzzer OFF; wait 1000 ms }
   How many milliseconds does this take in all?
8. 8.True or false: the ammeter measures voltage. (a) True (b) False
9. 9.📏 How many amperes (A) is 1230 mA? =
10. 10.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
11. 11.🔺 A current of 3 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
12. 12.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 230 V (c) 0.5 V (d) 1.5 V
13. 13.True or false: one tall, one short bar is the symbol for a bulb. (a) True (b) False
14. 14.🔍 Which sensor would you use to measure classroom noise? (a) a soil moisture sensor (b) a rain sensor (c) a gas sensor (d) a sound sensor
15. 15.True or false: a push button springs back when let go. (a) False (b) True
16. 16.🔍 Which is the odd one out? (a) dry your hands first (b) use mains for a project (c) poke things in a socket (d) climb an electric pole
17. 17.🔺 A current of 0.2 A flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
18. 18.True or false: “the pump turns on” is the output. (a) False (b) True
19. 19.💡 An LED is joined to a 6 V battery through a 1000 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) lights up (b) may burn out (c) does not light
20. 20.🌈 Which band is read first on a resistor? (a) any band (b) the one nearest an end (c) the widest gap (d) the gold band
21. 21.🔘 What does a switch do in a circuit? (a) stores current (b) opens or closes the loop (c) makes electricity (d) changes the voltage
22. 22.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is OFF. Does the bulb glow? (a) Yes (b) No
23. 23.🔌 Why are electric wires covered in plastic? (a) plastic is a conductor (b) to make them heavy (c) plastic is an insulator (d) plastic makes current
24. 24.📏 How many amperes (A) is 2000 mA? =
25. 25.🤖 Where does the board keep its program when the power is off? (a) the power LED (b) the USB cable (c) the resistor (d) flash memory
26. 26.⚡ A device works on 6 V and takes 3 A. What is its power (in watts)? =
27. 27.True or false: to dry your hands first is not safe. (a) True (b) False
28. 28.💡 A red LED uses 2 V and should get 20 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
29. 29.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 volt (c) 1 watt (d) 1 ampere
30. 30.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = I ÷ V (d) P = V ÷ I
31. 31.True or false: a glass marble is a conductor. (a) True (b) False
32. 32.⚠️ About how many volts do home sockets in India supply? (a) 12 V (b) 230 V (c) 9 V (d) 1.5 V
33. 33.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) an output (c) a fuse (d) a power source
34. 34.What does the sensor do? (a) stores data online (b) carries the data (c) measures the real world (d) acts on a command
35. 35.🔋 6 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
36. 36.⚙️ Which actuator would you use to show a status light? (a) a pump (b) an LED (c) a motor (d) a display
37. 37.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
38. 38.🔋 How many 3 V cells must be joined in series to give 15 V?
39. 39.True or false: to open a phone charger is not safe. (a) False (b) True
40. 40.📶 Digital or analog: a door: open or shut? (a) digital (b) analog

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