Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 111 · 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.🔐 Is it a good or a risky habit to share camera links? (a) good habit (b) risky habit
2. 2.True or false: to use old filament bulbs saves electricity. (a) False (b) True
3. 3.🔘 Which kind of switch stays where you flip it? (a) a tilt switch (b) a push button (c) a slide switch (d) a toggle switch
4. 4.🔺 A current of 40 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
5. 5.What does a reed switch do? (a) springs back when let go (b) flips up or down (c) stays where you flip it (d) closes near a magnet
6. 6.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) takes 1 away (c) adds 1 to count (d) prints 1
7. 7.⚡ Which tiny particles drift along a metal wire to carry the current? (a) dust particles (b) water drops (c) photons (d) electrons
8. 8.🧮 Four equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
9. 9.📏 Which unit measures voltage? (a) watt (W) (b) ohm (Ω) (c) ampere (A) (d) volt (V)
10. 10.💡 5 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. Does bulb 3 glow? (a) No (b) Yes
11. 11.🔁 x = 2
    repeat 4 times { x = x × 2 }
    What is x at the end?
12. 12.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V ÷ I (c) R = V × I (d) R = V + I
13. 13.⚠️ Is it safe to throw cells in a fire? (a) not safe (b) safe
14. 14.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
15. 15.True or false: on a cell, “the flat end” means the − (negative) end. (a) False (b) True
16. 16.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 60 (c) 100 (d) 1000
17. 17.🔍 Which is the odd one out? (a) a speaker (b) a push button (c) a motor (d) an LED
18. 18.🧾 A family uses 190 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
19. 19.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 350 ms }
    How many milliseconds does one blink (ON + OFF) take?
20. 20.⚡ A device works on 12 V and takes 1 A. What is its power (in watts)? =
21. 21.🔍 Which is the odd one out? (a) a ceramic cup (b) a plastic straw (c) a rubber eraser (d) a copper wire
22. 22.🔋 A 12 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
23. 23.⚡ What does a tube light mainly change electricity into? (a) light (b) sound (c) movement (d) heat
24. 24.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 450 ms }
    How many milliseconds does one blink (ON + OFF) take?
25. 25.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = V × I (d) P = I ÷ V
26. 26.⚠️ Which power source should children use for electronics projects? (a) a small battery pack (b) a mains extension board (c) an inverter socket (d) a wall socket
27. 27.🔺 A current of 3 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
28. 28.🗺️ In an input → process → output plan, is “the pump turns on” the input, the process or the output? (a) process (b) input (c) output
29. 29.True or false: a circle with A inside is the symbol for a bulb. (a) False (b) True
30. 30.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
31. 31.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
32. 32.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 3 seconds?
33. 33.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
34. 34.💡 In a series circuit, how many paths does the current have? (a) none (b) one for each bulb (c) two (d) one
35. 35.🔍 Which is the odd one out? (a) aluminium foil (b) a paper strip (c) a copper wire (d) an iron nail
36. 36.Which of these is safe? (a) poke things in a socket (b) fly a kite near wires (c) keep drinks far away (d) use mains for a project
37. 37.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 30 readings take?
38. 38.🗺️ In an input → process → output plan, is “decide if soil is dry” the input, the process or the output? (a) process (b) output (c) input
39. 39.🧮 A 20 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
40. 40.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the glass (d) the base

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