Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 94 · 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.🤖 “if (A AND B)” is true when … (a) only A is true (b) both are false (c) both A and B are true (d) only B is true
2. 2.⚡ A device works on 9 V and takes 3 A. What is its power (in watts)? =
3. 3.🔘 Which kind of switch flips up or down? (a) a toggle switch (b) a slide switch (c) a reed switch (d) a tilt switch
4. 4.🔋 What should you do with used-up cells? (a) bury them in soil (b) cut them open (c) throw them in a fire (d) give them for recycling
5. 5.True or false: a hand pump usually has a microcontroller inside. (a) False (b) True
6. 6.🌈 A resistor has the colour bands blue, grey, brown. What is its value (in ohms)?
7. 7.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = I ÷ V (c) R = V + I (d) R = V ÷ I
8. 8.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
9. 9.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = R ÷ V (c) I = V × R (d) I = V + R
10. 10.🔺 A 24 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
11. 11.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the pins (b) the voltage regulator (c) the USB port (d) the reset button
12. 12.🔍 Which sensor would you use to keep an incubator warm? (a) a rain sensor (b) a light sensor (c) a temperature sensor (d) a gas sensor
13. 13.🧮 Resistors of 50 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
14. 14.⚡ A 1.5 W device works on 1.5 V. What current does it take (in amperes)? =
15. 15.🧮 A 330 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
16. 16.🔢 To get a sensor reading onto a phone, what comes right after “the sensor measures”? (a) it is sent by Wi-Fi (b) the board reads it (c) the app shows it (d) the cloud stores it
17. 17.True or false: “how bright a room is” is an analog signal. (a) True (b) False
18. 18.🧾 A family uses 160 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
19. 19.Which of these is a risky habit? (a) log out of shared phones (b) change default passwords (c) turn off unused gadgets (d) share camera links
20. 20.True or false: to water a dry plant, use a soil moisture sensor. (a) True (b) False
21. 21.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 2 seconds?
22. 22.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) always zero (c) less than either one (d) their sum
23. 23.🔋 5 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
24. 24.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.💡 3 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
26. 26.📏 How many watts (W) is 2.7 kW?
27. 27.🔋 How many 2 V cells must be joined in series to give 8 V?
28. 28.🔌 Is a motion sensor an input or an output for a microcontroller? (a) input (b) output
29. 29.True or false: “a single current path” is true of a series circuit. (a) False (b) True
30. 30.🌈 In the resistor colour code, which number does yellow stand for?
31. 31.⚡ A device works on 5 V and takes 0.2 A. What is its power (in watts)? =
32. 32.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
33. 33.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
34. 34.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
35. 35.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 1.5 V (c) 230 V (d) 0.5 V
36. 36.True or false: to make a parking alarm, use a sound sensor. (a) True (b) False
37. 37.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) battery (b) diode (c) junction (d) capacitor
38. 38.True or false: on a cell, “the flat end” means the + (positive) end. (a) True (b) False
39. 39.🧩 Which component glows using little power? (a) diode (b) capacitor (c) resistor (d) LED
40. 40.⚡ A device works on 1.5 V and takes 3 A. What is its power (in watts)? =

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