Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 775 · 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.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V × R (c) I = R ÷ V (d) I = V + R
2. 2.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) it does not matter (d) only one
3. 3.💡 3 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. How many bulbs glow?
4. 4.⚡ Which formula gives electric power? (a) P = V + I (b) P = I ÷ V (c) P = V ÷ I (d) P = V × I
5. 5.⚙️ What is an actuator? (a) an output that acts (b) a program (c) a battery (d) a sensor
6. 6.🔋 Identical cells side by side (in parallel) give … (a) half the voltage (b) double the voltage (c) the same voltage (d) no voltage
7. 7.🌈 A resistor has the colour bands blue, grey, orange. What is its value (in ohms)?
8. 8.🔁 repeat 3 times { repeat 3 times { beep } }
   How many beeps are there?
9. 9.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
10. 10.True or false: a microcontroller runs many apps at once. (a) True (b) False
11. 11.💡 An LED is joined to a 12 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) lights up (b) may burn out (c) does not light
12. 12.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) pauses for half a second (c) turns the LED off (d) blinks 500 times
13. 13.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
14. 14.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) wavy lines (c) straight lines (d) little stars
15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
16. 16.🤖 Does a hand pump usually have a microcontroller inside? (a) Yes (b) No
17. 17.🌈 A resistor has the colour bands green, blue, red. What is its value in kilo-ohms (kΩ)? =
18. 18.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) all wires are joined (d) a wire is cut
19. 19.Which of these is not safe? (a) keep drinks far away (b) take cells out after use (c) poke things in a socket (d) stop if a part gets hot
20. 20.Which of these is an insulator? (a) a steel spoon (b) a steel coin (c) a metal paper clip (d) a plastic straw
21. 21.True or false: to spot someone walking in, use a light sensor. (a) True (b) False
22. 22.True or false: a safety pin is a conductor. (a) False (b) True
23. 23.⚠️ Who should be with you when you build a circuit? (a) a stranger online (b) a trusted adult (c) nobody (d) a younger child
24. 24.🌐 In an IoT system, which part stores data online? (a) phone app (b) cloud server (c) sensor (d) microcontroller
25. 25.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the base (d) the filament
26. 26.🔁 What does a variable do in a program? (a) stores a value (b) measures light (c) blinks an LED (d) joins two wires
27. 27.🔐 Who should decide which smart devices go in a child’s room? (a) nobody at all (b) an online stranger (c) the app’s adverts (d) a parent or guardian
28. 28.🧩 Which component blows if current is high? (a) LDR (b) thermistor (c) diode (d) fuse
29. 29.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) makes electricity (c) changes the voltage (d) stores current
30. 30.🔐 Is it a good or a risky habit to keep factory passwords? (a) good habit (b) risky habit
31. 31.True or false: “used in house wiring” is true of a series circuit. (a) True (b) False
32. 32.🤖 Does a plain wall switch usually have a microcontroller inside? (a) Yes (b) No
33. 33.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
34. 34.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) each gets full voltage (d) so all go off together
35. 35.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 150 readings take?
36. 36.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
37. 37.🔁 count = 5
    repeat 3 times { count = count + 2 }
    What is count at the end?
38. 38.True or false: a slide switch slides side to side. (a) False (b) True
39. 39.🔘 Which kind of switch stays where you flip it? (a) a slide switch (b) a toggle switch (c) a reed switch (d) a push button
40. 40.🔌 Is a plastic ruler a conductor or an insulator? (a) an insulator (b) a conductor

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