Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 872 · 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.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
2. 2.True or false: to cover unused cameras is a good habit. (a) True (b) False
3. 3.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
4. 4.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
5. 5.True or false: “the room temperature” is an analog signal. (a) True (b) False
6. 6.What does a fuse do? (a) makes things spin (b) senses how hot it is (c) smooths a wobbly supply (d) blows if current is high
7. 7.🔦 A circuit has a used-up (dead) 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 graphite rod. Does the bulb glow? (a) Yes (b) No
8. 8.💡 An LED is joined to a 6 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) may burn out (b) does not light (c) lights up
9. 9.Which of these is a risky habit? (a) set a strong password (b) log out of shared phones (c) change default passwords (d) keep factory passwords
10. 10.⏱️ A program says “wait 9500 ms”. How many seconds is that? =
11. 11.Which of these is a good habit? (a) tap unknown app links (b) read app permissions (c) accept every permission (d) share camera links
12. 12.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
13. 13.🧮 A 17 V battery is joined to 5 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
14. 14.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) the loop is complete (d) the bulb is unscrewed
15. 15.Which job is done by the voltage regulator? (a) runs the program (b) brings power and code (c) shows the board is on (d) keeps the voltage steady
16. 16.💡 An LED is joined to a 6 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) lights up (c) does not light
17. 17.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
18. 18.🔘 Which kind of switch slides side to side? (a) a reed switch (b) a toggle switch (c) a slide switch (d) a push button
19. 19.🤖 How does a new program get onto a microcontroller board? (a) sent by sound (b) uploaded over USB (c) drawn with a pen (d) typed on the chip
20. 20.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is OFF. Does the bulb glow? (a) Yes (b) No
21. 21.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 38 %. What happens? (a) pump OFF (b) pump ON
22. 22.Which of these is not an IoT device? (a) a fitness band with app (b) a Wi-Fi weather station (c) an app-controlled bulb (d) a pencil sharpener
23. 23.Which of these mainly makes movement? (a) a school bell (b) a ceiling fan (c) an LED lamp (d) a buzzer
24. 24.🔘 What does a switch do in a circuit? (a) makes electricity (b) changes the voltage (c) stores current (d) opens or closes the loop
25. 25.🔘 A bulb and a cell are joined through 6 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
26. 26.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
27. 27.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
28. 28.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) half the voltage (c) the same voltage (d) no voltage
29. 29.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
30. 30.Which of these is the process? (a) a button press (b) a soil moisture reading (c) the pump turns on (d) count button presses
31. 31.⏱️ A program says “wait 10000 ms”. How many seconds is that? =
32. 32.True or false: a washing machine usually has a microcontroller inside. (a) True (b) False
33. 33.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
34. 34.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) type it all in (b) post it online (c) share it with friends (d) ask a parent first
35. 35.True or false: two equal parallel lines is the symbol for a battery. (a) False (b) True
36. 36.🔌 Is a cotton thread a conductor or an insulator? (a) a conductor (b) an insulator
37. 37.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) energy used each second (d) the length of a wire
38. 38.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
39. 39.🔍 A distance sensor sends a sound pulse and hears the echo 17 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
40. 40.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True

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