Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 555 · 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.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are OFF (b) never (c) only when both are ON (d) when either is ON
2. 2.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) always zero (c) less than either one (d) their sum
3. 3.🔍 Which is the odd one out? (a) switch off empty rooms (b) use daylight to read (c) iron one shirt at a time (d) unplug idle chargers
4. 4.Which of these wastes electricity? (a) switch off empty rooms (b) leave fridge door open (c) close the fridge quickly (d) use daylight to read
5. 5.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
6. 6.True or false: a spinning top has no microcontroller inside. (a) True (b) False
7. 7.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
8. 8.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) no voltage (c) a smaller voltage (d) the same voltage
9. 9.🔐 Is it a good or a risky habit to cover unused cameras? (a) risky habit (b) good habit
10. 10.📏 Voltmeter or ammeter: which one is joined in series? (a) voltmeter (b) ammeter
11. 11.🔁 repeat 3 times { repeat 6 times { beep } }
    How many beeps are there?
12. 12.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
13. 13.⚡ A 1.2 W device works on 6 V. What current does it take (in amperes)? =
14. 14.True or false: a room heater mainly makes sound. (a) True (b) False
15. 15.⚡ A device works on 1.5 V and takes 0.2 A. What is its power (in watts)? =
16. 16.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a complete loop (d) a plastic gap
17. 17.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 5 V supply. What current flows (in mA)?
18. 18.🔍 Which is the odd one out? (a) a fitness band with app (b) a battery torch (c) a Wi-Fi doorbell camera (d) a Wi-Fi smart plug
19. 19.🤖 Does a spinning top usually have a microcontroller inside? (a) Yes (b) No
20. 20.🔐 Is it a good or a risky habit to share camera links? (a) risky habit (b) good habit
21. 21.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) adds 1 to count (d) prints 1
22. 22.🔍 A distance sensor sends a sound pulse and hears the echo 10 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
23. 23.Which of these gives us electricity? (a) a refrigerator (b) a computer (c) a washing machine (d) a wind turbine
24. 24.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
25. 25.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “the sensor measures”? (a) the app shows it (b) the sensor measures
26. 26.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
27. 27.⚙️ Which actuator would you use to spin a robot’s wheels? (a) an LED (b) a display (c) a pump (d) a motor
28. 28.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) False (b) True
29. 29.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
30. 30.🔍 Which is the odd one out? (a) install software updates (b) turn off unused gadgets (c) reuse one password (d) change default passwords
31. 31.True or false: to use daylight to read wastes electricity. (a) True (b) False
32. 32.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
34. 34.💡 An LED is joined to a 5 V battery with no 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
35. 35.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
36. 36.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
37. 37.Which of these is a risky habit? (a) read app permissions (b) turn off unused gadgets (c) log out of shared phones (d) accept every permission
38. 38.⏱️ A program says “wait 1000 ms”. How many seconds is that? =
39. 39.🔺 A 2 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
40. 40.🔍 Which is the odd one out? (a) a small display (b) a push button (c) a servo motor (d) a water pump

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