Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 399 · 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.⚙️ What is an actuator? (a) a program (b) an output that acts (c) a sensor (d) a battery
2. 2.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 60 (d) 10
3. 3.🔺 A current of 2.5 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
4. 4.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
5. 5.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
6. 6.⏱️ A program says “wait 4500 ms”. How many seconds is that? =
7. 7.🔍 Which is the odd one out? (a) turn off unused gadgets (b) ignore update messages (c) post your live location (d) keep factory passwords
8. 8.🔺 A current of 20 mA flows when 6.6 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.🤖 Does a bicycle bell usually have a microcontroller inside? (a) Yes (b) No
10. 10.🤖 Does a toy robot usually have a microcontroller inside? (a) Yes (b) No
11. 11.🤖 Does a microwave oven usually have a microcontroller inside? (a) Yes (b) No
12. 12.🔌 A gap of dry air between two wires acts as … (a) a cell (b) a conductor (c) an insulator (d) a switch that is ON
13. 13.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
14. 14.Which of these is true of a parallel circuit? (a) a single current path (b) many paths for current (c) one bulb out, all go out (d) bulbs share the voltage
15. 15.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
16. 16.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) the longer line (c) neither line (d) both lines
17. 17.⏱️ A program says “wait 8750 ms”. How many seconds is that? =
18. 18.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 2 glow? (a) No (b) Yes
19. 19.📏 How many ohms (Ω) is 0.4 kΩ?
20. 20.Which of these has no microcontroller inside? (a) a microwave oven (b) a digital thermometer (c) a washing machine (d) a hand pump
21. 21.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) changes the voltage (c) makes electricity (d) stores current
22. 22.Which job is done by the USB port? (a) brings power and code (b) restarts the program (c) runs the program (d) shows the board is on
23. 23.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
24. 24.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a capacitor (c) a diode (d) a buzzer
25. 25.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 200 ms }
    How many times does the LED blink in 5 seconds?
26. 26.True or false: the voltmeter is joined in series. (a) False (b) True
27. 27.🔐 Who should decide which smart devices go in a child’s room? (a) an online stranger (b) the app’s adverts (c) a parent or guardian (d) nobody at all
28. 28.🔍 Which is the odd one out? (a) a school bell (b) a doorbell (c) a loudspeaker (d) an electric kettle
29. 29.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a dry cork across the gap. Does the bulb glow? (a) Yes (b) No
30. 30.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic ruler across the gap. Does the bulb glow? (a) No (b) Yes
31. 31.True or false: a fuse makes a beeping sound. (a) True (b) False
32. 32.🔁 count = 0
    while (count < 30) { count = count + 5 }
    How many times does the loop run?
33. 33.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
34. 34.Which of these is not safe? (a) stop if a part gets hot (b) touch a fallen wire (c) use small battery cells (d) dry your hands first
35. 35.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 4 minutes?
36. 36.🧮 Five equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
37. 37.What does a tilt switch do? (a) slides side to side (b) closes near a magnet (c) flips up or down (d) closes when tipped over
38. 38.📶 Digital or analog: a door: open or shut? (a) analog (b) digital
39. 39.🔺 A current of 50 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
40. 40.🔍 Which is the odd one out? (a) a speaker (b) a buzzer (c) a small display (d) a keypad

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