Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 452 · 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.🤖 When the main loop of a microcontroller program ends, what happens? (a) it deletes itself (b) the board breaks (c) it stops forever (d) it starts again
2. 2.💡 What happens if an LED is put in backwards? (a) it does not light (b) it makes a sound (c) it changes colour (d) it lights brighter
3. 3.🔍 Which is the odd one out? (a) turn off unused gadgets (b) accept every permission (c) log out of shared phones (d) cover unused cameras
4. 4.🔋 How many 3 V cells must be joined in series to give 21 V?
5. 5.🔋 Does a refrigerator give electricity or use electricity? (a) uses electricity (b) gives electricity
6. 6.⚙️ Which actuator would you use to beep an alarm? (a) a pump (b) a motor (c) an LED (d) a buzzer
7. 7.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
8. 8.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) the length of a wire (d) energy used each second
9. 9.🔍 Which is the odd one out? (a) a cotton thread (b) an iron nail (c) a safety pin (d) a steel spoon
10. 10.🔍 Which sensor would you use to water a dry plant? (a) a gas sensor (b) a soil moisture sensor (c) a temperature sensor (d) a distance sensor
11. 11.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
12. 12.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a fitness band with app (c) a smart energy meter (d) a plain table fan
13. 13.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 2 cm. What happens? (a) buzzer is silent (b) buzzer beeps
14. 14.Which drawing is the symbol for a voltmeter? (a) triangle, bar and arrows (b) one tall, one short bar (c) a circle with V inside (d) two or more cell symbols
15. 15.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3.5 V supply. What current flows (in mA)?
16. 16.True or false: the voltmeter is joined across a part. (a) False (b) True
17. 17.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) a broken path (d) one loose end
18. 18.⚡ A 6 W device works on 3 V. What current does it take (in amperes)? =
19. 19.True or false: to switch on with a clap, use a soil moisture sensor. (a) False (b) True
20. 20.🔍 Which is the odd one out? (a) stop if a part gets hot (b) use small battery cells (c) touch a fallen wire (d) fly kites in open fields
21. 21.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) stay the same (d) smaller
22. 22.🤖 Does a microwave oven usually have a microcontroller inside? (a) No (b) Yes
23. 23.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
24. 24.🌐 In an IoT system, which part reads values, decides? (a) cloud server (b) microcontroller (c) actuator (d) sensor
25. 25.⚡ A 3 W device works on 6 V. What current does it take (in amperes)? =
26. 26.Which of these is a risky habit? (a) cover unused cameras (b) post your live location (c) install software updates (d) set up with a parent
27. 27.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the process (c) the input (d) the battery
28. 28.True or false: “own switch for each bulb” is true of a series circuit. (a) False (b) True
29. 29.True or false: a traffic signal mainly gives out light. (a) False (b) True
30. 30.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) sets count to 1 (d) takes 1 away
31. 31.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) none (c) two (d) one
32. 32.🔺 A current of 20 mA flows when 6.6 V is joined across a resistor. What is its resistance (in ohms)?
33. 33.True or false: a table fan mainly gives out light. (a) True (b) False
34. 34.🔍 Which is the odd one out? (a) a rice cooker (b) a mixer grinder (c) a toaster (d) a room heater
35. 35.Which of these is an insulator? (a) a metal paper clip (b) a safety pin (c) a graphite rod (d) a cotton thread
36. 36.📶 Digital or analog: the room temperature? (a) analog (b) digital
37. 37.🔋 3 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
38. 38.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 1000 (c) 100 (d) 60
39. 39.Which job is done by the USB port? (a) runs the program (b) shows the board is on (c) brings power and code (d) connect sensors and LEDs
40. 40.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 watt (d) 1 kilowatt-hour (kWh)

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