Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 483 · 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.🔺 A current of 0.2 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
2. 2.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False
3. 3.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) an input (c) a power source (d) a fuse
4. 4.🔁 What does “count = count + 1” do? (a) takes 1 away (b) prints 1 (c) adds 1 to count (d) sets count to 1
5. 5.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) Yes (b) No
6. 6.🔍 Which is the odd one out? (a) a steel spoon (b) a safety pin (c) a woollen thread (d) a brass key
7. 7.Which job needs a sound sensor? (a) close a window in rain (b) switch on with a clap (c) switch on lamps at dusk (d) start a fan when hot
8. 8.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 70000 Ω resistor? (a) grey-violet-orange (b) violet-black-red (c) violet-black-orange (d) violet-black-yellow
9. 9.🔁 What must there be for a current to flow? (a) a plastic gap (b) one loose end (c) a complete loop (d) a broken path
10. 10.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) a wire has come loose (d) a cell is taken out
11. 11.🔁 count = 7
    repeat 2 times { count = count + 2 }
    What is count at the end?
12. 12.🔘 When a switch is ON, the circuit is … (a) closed (b) cut (c) open (d) broken
13. 13.🧩 Which component blows if current is high? (a) fuse (b) transistor (c) buzzer (d) diode
14. 14.🔁 repeat 3 times { repeat 2 times { beep } }
    How many beeps are there?
15. 15.⚡ What does a toaster mainly change electricity into? (a) sound (b) heat (c) movement (d) light
16. 16.⏱️ repeat 3 times { buzzer ON; wait 700 ms; buzzer OFF; wait 800 ms }
    How many milliseconds does this take in all?
17. 17.🔺 A current of 25 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
18. 18.⚡ A device works on 9 V and takes 0.2 A. What is its power (in watts)? =
19. 19.⚡ Which formula gives electric power? (a) P = V + I (b) P = I ÷ V (c) P = V ÷ I (d) P = V × I
20. 20.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
21. 21.What does an LDR do? (a) makes a beeping sound (b) blows if current is high (c) boosts a small signal (d) senses how bright it is
22. 22.True or false: to unplug idle chargers saves electricity. (a) True (b) False
23. 23.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
24. 24.True or false: a rubber eraser is an insulator. (a) False (b) True
25. 25.💡 2 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. Does bulb 2 glow? (a) Yes (b) No
26. 26.🔁 count = 2
    repeat 5 times { count = count + 3 }
    What is count at the end?
27. 27.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) never (c) when either is ON (d) when both are ON
28. 28.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 5 % (d) 25 %
29. 29.🔍 Which is the odd one out? (a) a turning knob (b) a light sensor (c) a motor (d) a push button
30. 30.True or false: to open a phone charger is safe. (a) False (b) True
31. 31.Which of these is an output? (a) a light sensor (b) a push button (c) a sound sensor (d) a water pump
32. 32.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
33. 33.🧾 A family uses 20 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
34. 34.True or false: a circle with an X in it is the symbol for a wire. (a) False (b) True
35. 35.🗺️ In an input → process → output plan, is “a buzzer beeps” the input, the process or the output? (a) input (b) process (c) output
36. 36.🔍 Which sensor would you use to open blinds at sunrise? (a) a distance sensor (b) a gas sensor (c) a rain sensor (d) a light sensor
37. 37.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) ammeter (b) LED (c) resistor (d) diode
38. 38.🔍 A distance sensor sends a sound pulse and hears the echo 3 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
39. 39.🔍 Which is the odd one out? (a) keep drinks far away (b) use small battery cells (c) touch a switch when wet (d) fly kites in open fields
40. 40.⚡ What does an electric iron mainly change electricity into? (a) movement (b) heat (c) sound (d) light

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