Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 744 · 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.📏 How many kilo-ohms (kΩ) is 9200 Ω? =
2. 2.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) LED (b) battery (c) capacitor (d) switch
3. 3.Which drawing is the symbol for a diode? (a) a circle with M inside (b) triangle against a bar (c) a straight line (d) a circle with V inside
4. 4.Which of these is not safe? (a) touch a fallen wire (b) stay away from pylons (c) keep drinks far away (d) use small battery cells
5. 5.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 7 HIGH
   set pin 7 HIGH
   set pin 7 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
6. 6.🔘 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 OFF and D is ON. Does the bulb glow? (a) No (b) Yes
7. 7.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
8. 8.🧩 A capacitor in a circuit can … (a) make light (b) measure heat (c) store charge briefly (d) spin a wheel
9. 9.🔍 Which is the odd one out? (a) a button press (b) a soil moisture reading (c) a buzzer beeps (d) a light level reading
10. 10.🤖 “if (A AND B)” is true when … (a) both are false (b) only B is true (c) only A is true (d) both A and B are true
11. 11.📏 Which unit measures how much a part resists? (a) ohm (Ω) (b) volt (V) (c) watt (W) (d) ampere (A)
12. 12.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
13. 13.True or false: a resistor has coloured bands. (a) False (b) True
14. 14.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
15. 15.True or false: a microcontroller needs much more power. (a) False (b) True
16. 16.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
17. 17.Which of these is the process? (a) a button press (b) a motion sensor signal (c) check if temp > 30 (d) the fan starts
18. 18.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) one bulb out, all go out (c) a single current path (d) used in house wiring
19. 19.Which of these has no microcontroller inside? (a) a digital thermometer (b) a candle (c) a microwave oven (d) a TV remote
20. 20.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) wire (b) resistor (c) diode (d) cell
21. 21.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
22. 22.🔌 Is a light sensor an input or an output for a microcontroller? (a) output (b) input
23. 23.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 3.5 V supply. What current flows (in mA)?
24. 24.💡 An LED is joined to a 9 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) may burn out (b) does not light (c) lights up
25. 25.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
26. 26.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
27. 27.🔺 A current of 3 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
28. 28.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    set pin 8 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
29. 29.True or false: a metal paper clip is a conductor. (a) True (b) False
30. 30.🔌 Is a ceramic cup a conductor or an insulator? (a) a conductor (b) an insulator
31. 31.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) smaller (d) stay the same
32. 32.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
33. 33.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) pull them by the hand (b) wait and watch (c) pour water on them (d) shout for an adult
34. 34.🔁 x = 2
    repeat 3 times { x = x × 2 }
    What is x at the end?
35. 35.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a buzzer (d) a resistor
36. 36.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) only when both are ON (c) never (d) only when both are OFF
37. 37.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a plug top (b) a bulb (c) a long wire (d) a fuse or MCB
38. 38.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 kilowatt-hour (kWh) (d) 1 watt
39. 39.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
40. 40.🧩 Which component makes things spin? (a) thermistor (b) buzzer (c) motor (d) transistor

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