Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 710 · 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.Which of these is the input? (a) a buzzer beeps (b) the pump turns on (c) a button press (d) the fan starts
2. 2.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
3. 3.Which of these is a risky habit? (a) set up with a parent (b) set a strong password (c) install software updates (d) tap unknown app links
4. 4.What does the phone app do? (a) shows data to you (b) carries the data (c) reads values, decides (d) measures the real world
5. 5.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) parallel (b) series
6. 6.📶 How many states can a digital pin have? (a) ten (b) one (c) a thousand (d) two
7. 7.💡 2 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
8. 8.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
9. 9.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
10. 10.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) voltmeter (b) LED (c) motor (d) cell
11. 11.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) cell (b) resistor (c) ammeter (d) wire
12. 12.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to change its colour (c) to store charge (d) to make it brighter
13. 13.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 600 ms }
    How many times does the LED blink in 3 seconds?
14. 14.📏 How many kilowatts (kW) is 1050 W? =
15. 15.What does a tilt switch do? (a) flips up or down (b) closes near a magnet (c) closes when tipped over (d) works only while pressed
16. 16.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V ÷ R (c) I = V + R (d) I = R ÷ V
17. 17.⚙️ Which actuator would you use to move water to plants? (a) an LED (b) a pump (c) a motor (d) a display
18. 18.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
19. 19.🔋 4 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
20. 20.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) an open circuit (d) a full circuit
21. 21.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
22. 22.True or false: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
23. 23.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
24. 24.🔁 count = 3
    repeat 4 times { count = count + 7 }
    What is count at the end?
25. 25.🧮 Resistors of 100 Ω, 47 Ω, 50 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
26. 26.🔺 An 8 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
27. 27.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 110 readings take?
28. 28.🔍 Which sensor would you use to water a dry plant? (a) a light sensor (b) a motion sensor (c) a soil moisture sensor (d) a sound sensor
29. 29.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
30. 30.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
31. 31.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
32. 32.Which of these is an IoT device? (a) a paper calendar (b) a pencil sharpener (c) a battery torch (d) a fitness band with app
33. 33.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when both are OFF (c) when either is ON (d) when both are ON
34. 34.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) True (b) False
35. 35.Which of these is not safe? (a) fly kites in open fields (b) use small battery cells (c) stay away from pylons (d) touch a fallen wire
36. 36.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they keep glowing (c) they explode (d) they get dimmer
37. 37.True or false: to use daylight to read saves electricity. (a) False (b) True
38. 38.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
39. 39.🔘 Which kind of switch slides side to side? (a) a toggle switch (b) a reed switch (c) a slide switch (d) a tilt switch
40. 40.True or false: an LDR smooths a wobbly supply. (a) True (b) False

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids