Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 621 · 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.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they explode (c) they all go out (d) they keep glowing
2. 2.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an oil lamp (c) an LED lamp (d) a filament bulb
3. 3.🤖 “if (A AND B)” is true when … (a) only B is true (b) both A and B are true (c) both are false (d) only A is true
4. 4.Which of these is true of a series circuit? (a) many paths for current (b) used in house wiring (c) bulbs share the voltage (d) own switch for each bulb
5. 5.🤖 if (sound > 80) { red LED ON } else { green LED ON }
   The sound sensor reads 100. What happens? (a) green LED ON (b) red LED ON
6. 6.What does the phone app do? (a) shows data to you (b) stores data online (c) measures the real world (d) carries the data
7. 7.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
8. 8.🤖 if (sound > 80) { red LED ON } else { green LED ON }
   The sound sensor reads 90. What happens? (a) green LED ON (b) red LED ON
9. 9.🔍 Which is the odd one out? (a) the pump turns on (b) a buzzer beeps (c) decide if soil is dry (d) an alert on the phone
10. 10.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
11. 11.Which of these saves electricity? (a) set the AC to 24 °C (b) iron one shirt at a time (c) leave fridge door open (d) run fans in empty rooms
12. 12.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
13. 13.💡 5 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. Does bulb 2 glow? (a) No (b) Yes
14. 14.True or false: a toggle switch stays where you flip it. (a) False (b) True
15. 15.🔺 A current of 1 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
16. 16.True or false: two equal parallel lines is the symbol for a capacitor. (a) True (b) False
17. 17.🤖 Does a spinning top usually have a microcontroller inside? (a) Yes (b) No
18. 18.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 8 minutes?
19. 19.🔍 Which sensor would you use to stop a robot near walls? (a) a sound sensor (b) a temperature sensor (c) a distance sensor (d) a motion sensor
20. 20.🔍 Which is the odd one out? (a) share only needed data (b) install software updates (c) keep factory passwords (d) cover unused cameras
21. 21.🌈 A resistor has the colour bands grey, black, red. What is its value in kilo-ohms (kΩ)? =
22. 22.🔍 A distance sensor sends a sound pulse and hears the echo 6 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
23. 23.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 26 %. What happens? (a) pump ON (b) pump OFF
24. 24.📶 Digital or analog: a tilt switch: on or off? (a) digital (b) analog
25. 25.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) becomes zero (d) stays the same
26. 26.⏱️ repeat 7 times { buzzer ON; wait 400 ms; buzzer OFF; wait 700 ms }
    How many milliseconds does this take in all?
27. 27.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
28. 28.🔍 An object is 34 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
29. 29.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I + R (d) V = I × R
30. 30.⚠️ Is it safe to keep drinks far away? (a) not safe (b) safe
31. 31.💡 A red LED uses 2 V and should get 10 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
32. 32.⏱️ loop forever { LED ON; wait 850 ms; LED OFF; wait 50 ms }
    How many milliseconds does one blink (ON + OFF) take?
33. 33.💡 3 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
34. 34.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) when either is ON (c) only when both are OFF (d) never
35. 35.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) symbols are heavier (d) quick and clear for all
36. 36.⏱️ How many milliseconds is a wait of 4.3 seconds?
37. 37.📏 Which unit measures energy used each second? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
38. 38.🧾 A family uses 180 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
39. 39.🔢 To plan an electronics project, which is the FIRST step? (a) build it with an adult (b) draw the circuit diagram (c) pick a problem to solve (d) test it and fix it
40. 40.Which drawing is the symbol for a battery? (a) a small empty box (b) a circle with V inside (c) a dot where wires meet (d) two or more cell symbols

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