Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 668 · 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.⚡ A 2.25 W device works on 9 V. What current does it take (in amperes)? =
2. 2.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) True (b) False
3. 3.Which of these is a conductor? (a) a rubber band (b) a plastic straw (c) a wooden stick (d) a copper wire
4. 4.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 540 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
5. 5.Which of these is safe? (a) dry your hands first (b) poke things in a socket (c) open a phone charger (d) touch a switch when wet
6. 6.Which of these is safe? (a) open a phone charger (b) use small battery cells (c) use a cable with cuts (d) throw cells in a fire
7. 7.🔌 Is a small display an input or an output for a microcontroller? (a) output (b) input
8. 8.📏 How many kilowatts (kW) is 4150 W? =
9. 9.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
10. 10.🧩 Which component turns a fan or wheels? (a) fuse (b) diode (c) motor (d) capacitor
11. 11.True or false: a circle with A inside is the symbol for an ammeter. (a) False (b) True
12. 12.🔋 A 3 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
13. 13.Which of these is measured in amperes (A)? (a) energy used each second (b) the flow of charge (c) power (d) resistance
14. 14.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 850 ms }
    How many milliseconds does one blink (ON + OFF) take?
15. 15.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) Yes (b) No
16. 16.🔋 Identical cells side by side (in parallel) give … (a) the same voltage (b) double the voltage (c) half the voltage (d) no voltage
17. 17.True or false: the ammeter is joined across a part. (a) False (b) True
18. 18.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
19. 19.🔋 A 12 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
20. 20.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an LED lamp (d) an oil lamp
21. 21.📶 Digital or analog: how loud a sound is? (a) digital (b) analog
22. 22.True or false: a wooden stick is an insulator. (a) False (b) True
23. 23.🔺 A current of 0.5 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
24. 24.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) symbols are heavier (c) quick and clear for all (d) to make it colourful
25. 25.True or false: a resistor stores a little charge. (a) True (b) False
26. 26.⚙️ What is an actuator? (a) an output that acts (b) a sensor (c) a battery (d) a program
27. 27.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
28. 28.🔌 Most metals are good … (a) magnets only (b) insulators (c) conductors (d) batteries
29. 29.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) blinks 500 times (c) waits 500 seconds (d) turns the LED off
30. 30.True or false: “many paths for current” is true of a parallel circuit. (a) False (b) True
31. 31.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
32. 32.True or false: a microcontroller runs many apps at once. (a) True (b) False
33. 33.🔍 Which is the odd one out? (a) a light level reading (b) the pump turns on (c) an LED lights up (d) the fan starts
34. 34.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. How many bulbs glow?
35. 35.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) by Wi-Fi (c) in parallel (d) not joined
36. 36.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 42. What happens? (a) green LED ON (b) red LED ON
37. 37.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
38. 38.🧮 Resistors of 470 Ω, 68 Ω, 47 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
39. 39.True or false: two equal parallel lines is the symbol for a capacitor. (a) False (b) True
40. 40.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the if part (c) both parts (d) the else part

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