Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 6 · 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.💡 4 identical bulbs are in parallel and each one takes 0.2 A. What total current (in amperes) comes from the battery? =
2. 2.Which of these is safe? (a) open a phone charger (b) throw cells in a fire (c) stop if a part gets hot (d) use mains for a project
3. 3.💡 6 identical bulbs are in parallel and each bulb has its own switch on its path. 2 of the switches are OFF and the rest are ON. How many bulbs glow?
4. 4.🔁 count = 6
   repeat 5 times { count = count + 5 }
   What is count at the end?
5. 5.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 2.5 V supply. What current flows (in mA)?
6. 6.Which of these has no microcontroller inside? (a) a microwave oven (b) a smart watch (c) a toy robot (d) a plain wall switch
7. 7.⚡ What does an exhaust fan mainly change electricity into? (a) movement (b) sound (c) heat (d) light
8. 8.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) series (b) parallel
9. 9.Which of these usually has a microcontroller inside? (a) a wind-up toy (b) a microwave oven (c) a spinning top (d) a hand pump
10. 10.Which of these is a risky habit? (a) share only needed data (b) set a strong password (c) turn off unused gadgets (d) tap unknown app links
11. 11.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber eraser across the gap. Does the bulb glow? (a) Yes (b) No
12. 12.💡 In a series circuit, how many paths does the current have? (a) one (b) one for each bulb (c) none (d) two
13. 13.Which drawing is the symbol for a junction? (a) triangle, bar and arrows (b) one tall, one short bar (c) a plain rectangle (d) a dot where wires meet
14. 14.🌐 Is a battery torch an IoT device? (a) not an IoT device (b) an IoT device
15. 15.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) bulbs share the voltage (c) a single current path (d) used in house wiring
16. 16.Which of these is safe? (a) poke things in a socket (b) touch a fallen wire (c) use a cable with cuts (d) keep drinks far away
17. 17.True or false: on an LED, the leg by the flat edge is the anode (+). (a) True (b) False
18. 18.🌈 A resistor has the colour bands yellow, white, brown. What is its value (in ohms)?
19. 19.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) stays the same (d) becomes zero
20. 20.🔦 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
21. 21.🔗 Series or parallel circuit: “used in house wiring”? (a) series (b) parallel
22. 22.True or false: a circle with V inside is the symbol for a junction. (a) True (b) False
23. 23.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) both of them (d) only one
24. 24.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is OFF, B is OFF, C is OFF and D is ON. Does the bulb glow? (a) No (b) Yes
25. 25.🌐 Is an app-controlled bulb an IoT device? (a) not an IoT device (b) an IoT device
26. 26.Which of these is a risky habit? (a) share camera links (b) change default passwords (c) install software updates (d) turn off unused gadgets
27. 27.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) capacitor (b) LED (c) switch (d) battery
28. 28.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
29. 29.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
30. 30.🔍 Which sensor would you use to stop a robot near walls? (a) a sound sensor (b) a light sensor (c) a distance sensor (d) a gas sensor
31. 31.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) so all go off together (c) each gets full voltage (d) to save copper only
32. 32.🔘 Which kind of switch stays where you flip it? (a) a push button (b) a tilt switch (c) a toggle switch (d) a slide switch
33. 33.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the shorter line (c) both lines (d) the longer line
34. 34.True or false: a circle with A inside is the symbol for a bulb. (a) True (b) False
35. 35.🔺 A current of 50 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
36. 36.⚡ Which formula gives electric power? (a) P = V × I (b) P = V ÷ I (c) P = I ÷ V (d) P = V + I
37. 37.True or false: a slide switch works only while pressed. (a) False (b) True
38. 38.⚠️ Is it safe to fly kites in open fields? (a) not safe (b) safe
39. 39.💡 4 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
40. 40.⏱️ repeat 4 times { buzzer ON; wait 700 ms; buzzer OFF; wait 700 ms }
    How many milliseconds does this take in all?

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