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Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 589 · 40 questions
TalentJR

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.

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  1. 1.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  2. 2.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a filament bulb (c) a candle (d) an LED lamp
  3. 3.Which of these uses electricity? (a) a water pump (b) a bicycle dynamo (c) a power station (d) a solar panel
  4. 4.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) compare with the limit (b) switch the pump on/off (c) wait a few seconds (d) read the soil sensor
  5. 5.True or false: a plain wall switch has no microcontroller inside. (a) False (b) True
  6. 6.🔐 Is it a good or a risky habit to share the Wi-Fi key? (a) good habit (b) risky habit
  7. 7.💡 An LED is joined to a 9 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) lights up (c) does not light
  8. 8.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) False (b) True
  9. 9.🧮 Resistors of 68 Ω, 22 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
  10. 10.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 900 ms }
    How many times does the LED blink in 6 seconds?
  11. 11.🧾 A family uses 50 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  12. 12.⚡ A fan changes electrical energy mainly into which kind of energy? (a) light energy (b) chemical energy (c) movement energy (d) sound energy
  13. 13.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  14. 14.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the switch is OFF (d) all wires are joined
  15. 15.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
  16. 16.Which of these is the output? (a) the fan starts (b) a button press (c) compare with a limit (d) count button presses
  17. 17.⚠️ Is it safe to stay away from pylons? (a) not safe (b) safe
  18. 18.🌐 In an IoT system, which part acts on a command? (a) phone app (b) sensor (c) microcontroller (d) actuator
  19. 19.🔍 Which is the odd one out? (a) a loudspeaker (b) a doorbell (c) a torch (d) a buzzer
  20. 20.💡 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?
  21. 21.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets bigger (c) gets smaller (d) stays the same
  22. 22.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V × I (c) P = V ÷ I (d) P = V + I
  23. 23.⚠️ Is it safe to open a phone charger? (a) not safe (b) safe
  24. 24.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V + I (c) R = V ÷ I (d) R = V × I
  25. 25.⚡ A solar panel changes which kind of energy into electricity? (a) light energy (b) wind energy (c) chemical energy (d) sound energy
  26. 26.Which of these mainly gives out heat? (a) a table fan (b) a night lamp (c) a torch (d) an electric kettle
  27. 27.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water pressure (b) the water tank lid (c) the pipe colour (d) the tap handle
  28. 28.Which of these is measured in watts (W)? (a) voltage (b) resistance (c) current (d) power
  29. 29.True or false: a laptop has a built-in keyboard. (a) True (b) False
  30. 30.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
  31. 31.True or false: power is measured in volts (V). (a) False (b) True
  32. 32.🔍 Which is the odd one out? (a) set up with a parent (b) accept every permission (c) set a strong password (d) turn off unused gadgets
  33. 33.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a resistor (c) a diode (d) a capacitor
  34. 34.🔋 7 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
  35. 35.⚠️ Is it safe to build with an adult near? (a) safe (b) not safe
  36. 36.True or false: an electric drill mainly gives out light. (a) True (b) False
  37. 37.📶 A pin set LOW gives about … (a) 0 V (b) 1.5 V (c) 9 V (d) 5 V
  38. 38.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 6 V supply. What current flows (in mA)?
  39. 39.📶 On a 5 V board, a pin set HIGH gives about … (a) 5 V (b) 230 V (c) 50 V (d) 0 V
  40. 40.⚡ What does a doorbell mainly change electricity into? (a) light (b) movement (c) heat (d) sound

Answer key

  1. 0.5
  2. an LED lamp
  3. a water pump
  4. read the soil sensor
  5. True
  6. risky habit
  7. may burn out
  8. True
  9. 112
  10. 6
  11. 200
  12. movement energy
  13. anode (+)
  14. the switch is OFF
  15. No
  16. the fan starts
  17. safe
  18. actuator
  19. a torch
  20. 1000
  21. gets smaller
  22. P = V × I
  23. not safe
  24. R = V ÷ I
  25. light energy
  26. an electric kettle
  27. the water pressure
  28. power
  29. True
  30. stores a value
  31. False
  32. accept every permission
  33. a buzzer
  34. 14
  35. safe
  36. False
  37. 0 V
  38. 20
  39. 5 V
  40. sound

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