Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 307 · 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.📶 Digital or analog: how loud a sound is? (a) analog (b) digital
2. 2.🔺 A 3 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
3. 3.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) diode (b) motor (c) LED (d) cell
4. 4.⚠️ Is it safe to throw cells in a fire? (a) not safe (b) safe
5. 5.🔍 Which is the odd one out? (a) switch off empty rooms (b) use LED lamps (c) use daylight to read (d) leave the TV on standby
6. 6.💡 What does LED stand for? (a) light-emitting diode (b) light energy dial (c) low energy device (d) large electric dial
7. 7.🔍 Which is the odd one out? (a) an iron nail (b) aluminium foil (c) a steel spoon (d) a ceramic cup
8. 8.🔦 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
9. 9.Which drawing is the symbol for a capacitor? (a) two or more cell symbols (b) a circle with A inside (c) triangle against a bar (d) two equal parallel lines
10. 10.🧮 A 10 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
11. 11.💡 An LED is joined to a 9 V battery through a 1000 Ω 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.🔘 Which kind of switch flips up or down? (a) a push button (b) a reed switch (c) a slide switch (d) a toggle switch
13. 13.🔍 A distance sensor sends a sound pulse and hears the echo 2 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
14. 14.⚡ What does a mixer grinder mainly change electricity into? (a) movement (b) sound (c) light (d) heat
15. 15.Which of these is safe? (a) open a phone charger (b) use small battery cells (c) fly a kite near wires (d) throw cells in a fire
16. 16.🔋 4 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
17. 17.What does a toggle switch do? (a) springs back when let go (b) closes when tipped over (c) slides side to side (d) flips up or down
18. 18.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) each gets full voltage (c) to save copper only (d) so all go off together
19. 19.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
20. 20.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
22. 22.🌐 Is a fitness band with app an IoT device? (a) not an IoT device (b) an IoT device
23. 23.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) list inputs and outputs (b) build it with an adult (c) test it and fix it (d) pick a problem to solve
24. 24.True or false: triangle, bar and arrows is the symbol for an LED. (a) False (b) True
25. 25.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) in series (c) not joined (d) by Wi-Fi
26. 26.🔌 Most metals are good … (a) magnets only (b) batteries (c) conductors (d) insulators
27. 27.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
28. 28.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) never (b) when either is ON (c) only when both are OFF (d) only when both are ON
29. 29.⚙️ What is an actuator? (a) a battery (b) an output that acts (c) a program (d) a sensor
30. 30.🔐 Is it a good or a risky habit to set up with a parent? (a) risky habit (b) good habit
31. 31.True or false: “each gets the full volts” is true of a series circuit. (a) False (b) True
32. 32.Which of these is a conductor? (a) a brass key (b) a rubber eraser (c) a wooden stick (d) a plastic straw
33. 33.💡 A battery lights 5 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
34. 34.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the switch is OFF
35. 35.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 50 %. What happens? (a) pump OFF (b) pump ON
36. 36.🧾 A family uses 170 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
37. 37.Which of these is not an IoT device? (a) a fitness band with app (b) a Wi-Fi doorbell camera (c) a plain wall switch (d) a Wi-Fi smart plug
38. 38.🔐 Is it a good or a risky habit to post your live location? (a) risky habit (b) good habit
39. 39.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) LED (b) battery (c) resistor (d) junction
40. 40.🔗 Series or parallel circuit: “used in house wiring”? (a) series (b) parallel

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