Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 531 · 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.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
2. 2.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is ON, C is ON and D is ON. Does the bulb glow? (a) No (b) Yes
3. 3.🔍 Which is the odd one out? (a) a temperature reading (b) a button press (c) a motion sensor signal (d) an LED lights up
4. 4.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) neither part (c) the else part (d) both parts
5. 5.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 300 ms }
   How many times does the LED blink in 8 seconds?
6. 6.🔁 What does a variable do in a program? (a) joins two wires (b) stores a value (c) blinks an LED (d) measures light
7. 7.⚙️ Which actuator would you use to show the temperature? (a) a servo motor (b) a pump (c) a motor (d) a display
8. 8.🔘 Which kind of switch closes near a magnet? (a) a slide switch (b) a push button (c) a reed switch (d) a toggle switch
9. 9.🔘 A bulb and a cell are joined through 5 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
10. 10.🤖 Does a bicycle bell usually have a microcontroller inside? (a) No (b) Yes
11. 11.🔺 A current of 0.2 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
12. 12.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a mains extension board (c) a wall socket (d) a small battery pack
13. 13.🔍 Which is the odd one out? (a) a traffic signal (b) a night lamp (c) a siren (d) a torch
14. 14.📶 A pin that reads a push button is set as … (a) a resistor (b) an output (c) an input (d) a battery
15. 15.🗺️ In an input → process → output plan, is “check if temp > 30” the input, the process or the output? (a) input (b) output (c) process
16. 16.🧾 A family uses 140 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
17. 17.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) any band (c) the gold band (d) the widest gap
18. 18.🗺️ In an input → process → output plan, is “an LED lights up” the input, the process or the output? (a) input (b) process (c) output
19. 19.🌈 In the resistor colour code, which number does grey stand for?
20. 20.Which of these usually has a microcontroller inside? (a) a hand pump (b) a bicycle bell (c) a wind-up toy (d) a digital alarm clock
21. 21.🔐 Is it a good or a risky habit to install software updates? (a) risky habit (b) good habit
22. 22.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
23. 23.Which drawing is the symbol for a motor? (a) a circle with V inside (b) a circle with a cross (c) a circle with an X in it (d) a circle with M inside
24. 24.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 25 % (c) 5 % (d) 0 %
25. 25.🔘 Which kind of switch closes when tipped over? (a) a tilt switch (b) a toggle switch (c) a reed switch (d) a slide switch
26. 26.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) dotted circles (c) wavy lines (d) straight lines
27. 27.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
28. 28.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
29. 29.📶 A pin set LOW gives about … (a) 1.5 V (b) 5 V (c) 9 V (d) 0 V
30. 30.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) LED (b) switch (c) cell (d) capacitor
31. 31.🔍 An object is 17 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
32. 32.Which of these is an IoT device? (a) a Wi-Fi smart plug (b) a battery torch (c) a pencil sharpener (d) a plain table fan
33. 33.What does the Wi-Fi link do? (a) shows data to you (b) carries the data (c) measures the real world (d) reads values, decides
34. 34.🔋 Identical cells side by side (in parallel) give … (a) half the voltage (b) the same voltage (c) no voltage (d) double the voltage
35. 35.True or false: a glass marble is an insulator. (a) True (b) False
36. 36.Which of these is a good habit? (a) reuse one password (b) post your live location (c) share the Wi-Fi key (d) set up with a parent
37. 37.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 330 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
38. 38.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) a wire has come loose (d) the switch is OFF
39. 39.🔺 A current of 2 A flows when 40 V is joined across a resistor. What is its resistance (in ohms)?
40. 40.Which job needs a rain sensor? (a) measure classroom noise (b) close a window in rain (c) spot someone walking in (d) keep an incubator warm

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