Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 438 · 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.🧮 Resistors of 20 Ω, 68 Ω, 220 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
2. 2.✏️ In a circuit diagram, which part is drawn as a circle with V inside? (a) voltmeter (b) battery (c) junction (d) ammeter
3. 3.🔐 Is it a good or a risky habit to set a strong password? (a) risky habit (b) good habit
4. 4.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a cell is taken out (d) all wires are joined
5. 5.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
6. 6.🧮 Two resistors in parallel give a total that is … (a) their sum (b) more than either one (c) always zero (d) less than either one
7. 7.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) close the fridge quickly (c) use daylight to read (d) iron one shirt at a time
8. 8.⚡ A fan changes electrical energy mainly into which kind of energy? (a) sound energy (b) movement energy (c) light energy (d) chemical energy
9. 9.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 watt
10. 10.🔍 Which is the odd one out? (a) a cotton thread (b) a safety pin (c) aluminium foil (d) a copper wire
11. 11.Which of these is true of a series circuit? (a) each gets the full volts (b) many paths for current (c) one out, the rest glow (d) a single current path
12. 12.🔋 Does a battery give electricity or use electricity? (a) uses electricity (b) gives electricity
13. 13.What does a resistor do? (a) blows if current is high (b) beeps for an alarm (c) is a resistance knob (d) limits the current
14. 14.True or false: a microcontroller runs one small program. (a) True (b) False
15. 15.🌈 A resistor has the colour bands blue, brown, black. What is its value (in ohms)?
16. 16.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
17. 17.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
18. 18.💡 2 identical bulbs are joined in parallel across a 3 V battery (ideal wires). How many volts does each bulb get? =
19. 19.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets smaller (d) gets bigger
20. 20.True or false: the flow of charge is measured in volts (V). (a) True (b) False
21. 21.Which of these is measured in ohms (Ω)? (a) current (b) energy used each second (c) power (d) resistance
22. 22.🔍 Which is the odd one out? (a) install software updates (b) turn off unused gadgets (c) change default passwords (d) share the Wi-Fi key
23. 23.⚡ A device works on 3 V and takes 3 A. What is its power (in watts)? =
24. 24.⚡ What does a table fan mainly change electricity into? (a) light (b) sound (c) movement (d) heat
25. 25.⚡ A device works on 5 V and takes 3 A. What is its power (in watts)? =
26. 26.🧮 Resistors of 33 Ω, 20 Ω, 330 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
27. 27.True or false: “a single current path” is true of a series circuit. (a) True (b) False
28. 28.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 7 seconds?
29. 29.Which of these is safe? (a) open a phone charger (b) touch a switch when wet (c) use a cable with cuts (d) use small battery cells
30. 30.🔍 Which is the odd one out? (a) a pencil sharpener (b) a plain wall switch (c) a plain table fan (d) a smart energy meter
31. 31.What does a buzzer do? (a) boosts a small signal (b) senses how bright it is (c) stores a little charge (d) beeps for an alarm
32. 32.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
33. 33.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = I ÷ V (d) P = V + I
34. 34.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) never (b) when either is ON (c) only when both are OFF (d) only when both are ON
35. 35.🔦 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
36. 36.🔦 A circuit has a used-up (dead) 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 dry cork. Does the bulb glow? (a) No (b) Yes
37. 37.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the if part (c) the else part (d) both parts
38. 38.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
39. 39.🔁 x = 1
    repeat 5 times { x = x × 2 }
    What is x at the end?
40. 40.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 25) { show “Warm” } else { show “Cool” }
    The temperature is 14 °C. What is shown? (a) Warm (b) Cool (c) Hot

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