Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 596 · 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.What does a fuse do? (a) blows if current is high (b) senses how bright it is (c) has coloured bands (d) makes things spin
2. 2.Which of these means the circuit is closed? (a) a wire is cut (b) all wires are joined (c) a cell is taken out (d) a wire has come loose
3. 3.True or false: current is measured in volts (V). (a) True (b) False
4. 4.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V × I (c) R = V + I (d) R = V ÷ I
5. 5.⚡ Which formula gives electric power? (a) P = V × I (b) P = V ÷ I (c) P = V + I (d) P = I ÷ V
6. 6.🤖 Does a bicycle bell usually have a microcontroller inside? (a) Yes (b) No
7. 7.True or false: a rice cooker mainly makes movement. (a) False (b) True
8. 8.🌈 A resistor has the colour bands blue, brown, orange. What is its value (in ohms)?
9. 9.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) stores a value (d) joins two wires
10. 10.⚡ A solar panel changes which kind of energy into electricity? (a) wind energy (b) sound energy (c) light energy (d) chemical energy
11. 11.True or false: “a break stops every bulb” is true of a series circuit. (a) True (b) False
12. 12.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V + R (c) I = V ÷ R (d) I = R ÷ V
13. 13.What does an LED do? (a) blows if current is high (b) glows using little power (c) senses how hot it is (d) stores a little charge
14. 14.🧩 Which component boosts a small signal? (a) transistor (b) LED (c) resistor (d) potentiometer
15. 15.⚠️ Is it safe to climb an electric pole? (a) safe (b) not safe
16. 16.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
17. 17.🔍 Which is the odd one out? (a) a room heater (b) a siren (c) an electric iron (d) a water heater
18. 18.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a safe circuit (b) a short circuit (c) a parallel circuit (d) an open circuit
19. 19.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
20. 20.⚡ A cell changes stored chemical energy into which kind of energy? (a) nuclear energy (b) sound energy (c) wind energy (d) electrical energy
21. 21.✏️ In a circuit diagram, which part is drawn as a circle with V inside? (a) motor (b) switch (c) voltmeter (d) battery
22. 22.⚡ A 0.75 W device works on 3 V. What current does it take (in amperes)? =
23. 23.True or false: a circle with M inside is the symbol for an LED. (a) False (b) True
24. 24.What does the microcontroller do? (a) measures the real world (b) stores data online (c) carries the data (d) reads values, decides
25. 25.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) False (b) True
26. 26.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is ON. Does the bulb glow? (a) Yes (b) No
27. 27.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the main chip (b) the reset button (c) the USB port (d) the voltage regulator
28. 28.Which job needs a servo motor? (a) show the temperature (b) spin a robot’s wheels (c) show a status light (d) open a gate to 90°
29. 29.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
30. 30.Which of these wastes electricity? (a) use old filament bulbs (b) unplug idle chargers (c) use LED lamps (d) switch off empty rooms
31. 31.💡 Why does an LED need a resistor in series? (a) to change its colour (b) to make it brighter (c) to store charge (d) to limit the current
32. 32.🔍 Which sensor would you use to open blinds at sunrise? (a) a light sensor (b) a gas sensor (c) a temperature sensor (d) a sound sensor
33. 33.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 48 %. What happens? (a) pump ON (b) pump OFF
34. 34.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
35. 35.🌐 What does IoT stand for? (a) Internet of Things (b) Internet of Talk (c) Input of Tools (d) Inside of Toys
36. 36.🌈 A resistor has the colour bands red, violet, red. What is its value in kilo-ohms (kΩ)? =
37. 37.🧮 Resistors of 100 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
38. 38.🧮 Two equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
39. 39.🔍 Which is the odd one out? (a) switch off empty rooms (b) set the AC to 24 °C (c) iron one shirt at a time (d) use LED lamps
40. 40.Which job is done by the pins? (a) restarts the program (b) runs the program (c) shows the board is on (d) connect sensors and LEDs

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