Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 327 · 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.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
2. 2.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
3. 3.True or false: “HIGH or LOW only” is an analog signal. (a) True (b) False
4. 4.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
5. 5.🔁 total = 0
   for i = 1 to 12 { total = total + i }
   What is total at the end?
6. 6.Which of these is true of a parallel circuit? (a) used in house wiring (b) bulbs share the voltage (c) a break stops every bulb (d) one bulb out, all go out
7. 7.🔋 A 3 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
8. 8.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
9. 9.💡 What does LED stand for? (a) light energy dial (b) low energy device (c) light-emitting diode (d) large electric dial
10. 10.Which of these is an output? (a) a push button (b) an LED (c) a keypad (d) a light sensor
11. 11.🔁 count = 8
    repeat 4 times { count = count + 8 }
    What is count at the end?
12. 12.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
13. 13.True or false: a potentiometer is a resistance knob. (a) False (b) True
14. 14.🌐 Is a smart energy meter an IoT device? (a) an IoT device (b) not an IoT device
15. 15.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
16. 16.🔘 A bulb and a cell are joined through 5 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
17. 17.🔋 Does a refrigerator give electricity or use electricity? (a) uses electricity (b) gives electricity
18. 18.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is ON and B is OFF. Does the bulb glow? (a) No (b) Yes
19. 19.Which of these is not safe? (a) fly kites in open fields (b) stop if a part gets hot (c) touch a fallen wire (d) stay away from pylons
20. 20.🗺️ Before building a project, what should you write down first? (a) the box colour (b) nothing at all (c) inputs and outputs (d) the final price
21. 21.⚙️ Which actuator would you use to beep an alarm? (a) an LED (b) a pump (c) a buzzer (d) a display
22. 22.🔺 A current of 0.1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
23. 23.📏 How many amperes (A) is 1350 mA? =
24. 24.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
25. 25.⏱️ How many milliseconds is a wait of 0.7 seconds?
26. 26.Which of these saves electricity? (a) leave the TV on standby (b) unplug idle chargers (c) leave fridge door open (d) run fans in empty rooms
27. 27.🧮 A 33 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
28. 28.True or false: a long and a short line is the symbol for an LED. (a) True (b) False
29. 29.Which job is done by the reset button? (a) restarts the program (b) keeps the voltage steady (c) brings power and code (d) connect sensors and LEDs
30. 30.⏱️ loop forever { LED ON; wait 600 ms; LED OFF; wait 950 ms }
    How many milliseconds does one blink (ON + OFF) take?
31. 31.True or false: the push of a cell is measured in ohms (Ω). (a) False (b) True
32. 32.Which of these mainly gives out light? (a) an electric toy car (b) an electric drill (c) a buzzer (d) a torch
33. 33.True or false: a push button springs back when let go. (a) False (b) True
34. 34.True or false: on an LED, the longer leg is the anode (+). (a) False (b) True
35. 35.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) close the fridge quickly (d) iron one shirt at a time
36. 36.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
37. 37.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a resistor (c) an LED (d) a motor
38. 38.⚡ A device works on 1.5 V and takes 0.1 A. What is its power (in watts)? =
39. 39.🔺 A 1.25 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
40. 40.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) energy used each second (d) the size of a cell

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