Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 67 · 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.🔋 5 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
2. 2.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
3. 3.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
   The distance sensor reads 18 cm. What happens? (a) buzzer is silent (b) buzzer beeps
4. 4.📏 How many amperes (A) is 830 mA? =
5. 5.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) No (b) Yes
6. 6.💡 3 identical bulbs are joined in series with a 9 V battery (ideal wires). How many volts does each bulb get? =
7. 7.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 2400 Ω resistor? (a) yellow-red-red (b) red-yellow-brown (c) red-yellow-orange (d) red-yellow-red
8. 8.Which of these is true of a series circuit? (a) many paths for current (b) each gets the full volts (c) one out, the rest glow (d) a break stops every bulb
9. 9.🤖 Microcontroller or laptop: which one has no screen of its own? (a) laptop (b) microcontroller
10. 10.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 50 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
11. 11.🔌 Is a copper wire a conductor or an insulator? (a) an insulator (b) a conductor
12. 12.🔺 A current of 25 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🔍 Which sensor would you use to spot someone walking in? (a) a soil moisture sensor (b) a light sensor (c) a distance sensor (d) a motion sensor
14. 14.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) a cell is taken out (d) the loop is complete
15. 15.🔦 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) No (b) Yes
16. 16.Which of these is a risky habit? (a) turn off unused gadgets (b) ignore update messages (c) share only needed data (d) change default passwords
17. 17.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
18. 18.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) False (b) True
19. 19.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
20. 20.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
21. 21.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
22. 22.⚙️ Which actuator would you use to move water to plants? (a) a display (b) a motor (c) a servo motor (d) a pump
23. 23.Which of these is safe? (a) keep drinks far away (b) poke things in a socket (c) use mains for a project (d) open a phone charger
24. 24.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
25. 25.🔁 x = 4
    repeat 1 time { x = x × 2 }
    What is x at the end?
26. 26.🤖 Does a spinning top usually have a microcontroller inside? (a) Yes (b) No
27. 27.⚠️ About how many volts do home sockets in India supply? (a) 12 V (b) 230 V (c) 9 V (d) 1.5 V
28. 28.🔺 A current of 3 A flows when 24 V is joined across a resistor. What is its resistance (in ohms)?
29. 29.Which job needs a motor? (a) show a status light (b) spin a robot’s wheels (c) open a gate to 90° (d) beep an alarm
30. 30.🔺 A current of 1 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
31. 31.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
32. 32.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
33. 33.🔍 A distance sensor sends a sound pulse and hears the echo 9 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
34. 34.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) Yes (b) No
35. 35.🔢 To plan an electronics project, which comes first: “build it with an adult” or “list inputs and outputs”? (a) list inputs and outputs (b) build it with an adult
36. 36.Which of these is true of a series circuit? (a) one out, the rest glow (b) many paths for current (c) used in house wiring (d) bulbs share the voltage
37. 37.🔋 7 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)? =
38. 38.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
39. 39.Which drawing is the symbol for a battery? (a) one tall, one short bar (b) many long-short pairs (c) a circle with an X in it (d) a straight line
40. 40.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) symbols are heavier (c) to hide the circuit (d) quick and clear for all

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