Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 191 · 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) an alert on the phone (c) a light level reading (d) an LED lights up
2. 2.⏱️ How many milliseconds is a wait of 1.9 seconds?
3. 3.Which of these uses electricity? (a) a battery (b) a computer (c) a generator (d) a cell
4. 4.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) joins two wires (d) stores a value
5. 5.🔺 A 5 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
6. 6.Which of these is a good habit? (a) keep factory passwords (b) share the Wi-Fi key (c) set a strong password (d) accept every permission
7. 7.Which job needs a distance sensor? (a) close a window in rain (b) water a dry plant (c) stop a robot near walls (d) open blinds at sunrise
8. 8.🔦 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) No (b) Yes
9. 9.What does a transistor do? (a) makes a beeping sound (b) glows using little power (c) lets current go one way (d) boosts a small signal
10. 10.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) a fuse (c) an output (d) an input
11. 11.📏 Which unit measures how much a part resists? (a) ohm (Ω) (b) volt (V) (c) watt (W) (d) ampere (A)
12. 12.Which of these is a good habit? (a) share the Wi-Fi key (b) ignore update messages (c) share only needed data (d) keep factory passwords
13. 13.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. How many bulbs glow?
14. 14.What does an LDR do? (a) beeps for an alarm (b) makes a beeping sound (c) senses how bright it is (d) blows if current is high
15. 15.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is OFF, B is OFF, C is OFF and D is OFF. Does the bulb glow? (a) Yes (b) No
16. 16.🌈 A resistor has the colour bands yellow, violet, orange. What is its value (in ohms)?
17. 17.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) series (b) parallel
18. 18.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
19. 19.True or false: energy used each second is measured in watts (W). (a) False (b) True
20. 20.🔺 A 12.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
21. 21.🤖 Does a plain wall switch usually have a microcontroller inside? (a) No (b) Yes
22. 22.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
23. 23.🔍 Which is the odd one out? (a) a siren (b) a doorbell (c) an electric iron (d) a buzzer
24. 24.⚡ A 0.6 W device works on 3 V. What current does it take (in amperes)? =
25. 25.⏱️ A program says “wait 7000 ms”. How many seconds is that? =
26. 26.🔘 Which kind of switch works only while pressed? (a) a push button (b) a toggle switch (c) a reed switch (d) a tilt switch
27. 27.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
28. 28.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) the loop is complete (d) a wire has come loose
29. 29.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
30. 30.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 7 seconds?
31. 31.True or false: “the fan starts” is the process. (a) True (b) False
32. 32.Which of these is an insulator? (a) an iron nail (b) a brass key (c) a paper strip (d) a safety pin
33. 33.🔍 Which is the odd one out? (a) keep drinks far away (b) fly kites in open fields (c) build with an adult near (d) fly a kite near wires
34. 34.🌐 Is a wind-up clock an IoT device? (a) an IoT device (b) not an IoT device
35. 35.True or false: to share the Wi-Fi key is a good habit. (a) True (b) False
36. 36.🧮 Resistors of 10 Ω, 22 Ω, 470 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
37. 37.Which drawing is the symbol for a diode? (a) a straight line (b) triangle against a bar (c) a circle with V inside (d) a circle with A inside
38. 38.True or false: on an LED, the leg by the flat edge is the anode (+). (a) True (b) False
39. 39.True or false: a resistor smooths a wobbly supply. (a) True (b) False
40. 40.🔁 count = 0
    repeat 5 times { count = count + 4 }
    What is count at the end?

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