Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 355 · 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.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = I ÷ V (c) P = V × I (d) P = V + I
2. 2.💡 In a series circuit, how many paths does the current have? (a) none (b) two (c) one for each bulb (d) one
3. 3.🌈 A resistor has the colour bands brown, black, orange. What is its value in kilo-ohms (kΩ)? =
4. 4.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a parallel circuit (b) an open circuit (c) a short circuit (d) a safe circuit
5. 5.True or false: on an LED, the longer leg is the anode (+). (a) False (b) True
6. 6.🗺️ In an input → process → output plan, is “the fan starts” the input, the process or the output? (a) input (b) output (c) process
7. 7.⚠️ About how many volts do home sockets in India supply? (a) 9 V (b) 1.5 V (c) 12 V (d) 230 V
8. 8.True or false: “a light level reading” is the input. (a) False (b) True
9. 9.⚡ Power tells us … (a) energy used each second (b) the colour of light (c) the size of a cell (d) the length of a wire
10. 10.🧩 Which component lets current go one way? (a) LDR (b) diode (c) capacitor (d) resistor
11. 11.🔘 What does a switch do in a circuit? (a) makes electricity (b) changes the voltage (c) opens or closes the loop (d) stores current
12. 12.🌐 In an IoT system, which part reads values, decides? (a) cloud server (b) sensor (c) actuator (d) microcontroller
13. 13.🧩 Which component is a resistance knob? (a) LDR (b) fuse (c) buzzer (d) potentiometer
14. 14.💡 5 identical bulbs are in parallel and each bulb has its own switch on its path. 3 of the switches are OFF and the rest are ON. How many bulbs glow?
15. 15.Which drawing is the symbol for a switch? (a) one tall, one short bar (b) a dot where wires meet (c) a line lifted at a gap (d) triangle against a bar
16. 16.🔍 Which is the odd one out? (a) a paper strip (b) a rubber band (c) a rubber eraser (d) a copper wire
17. 17.Which of these is the input? (a) check if temp > 30 (b) the fan starts (c) a motion sensor signal (d) an alert on the phone
18. 18.What does the actuator do? (a) reads values, decides (b) carries the data (c) acts on a command (d) measures the real world
19. 19.🧮 Resistors of 47 Ω, 330 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
20. 20.True or false: a long and a short line is the symbol for a battery. (a) True (b) False
21. 21.🔢 To get a sensor reading onto a phone, which comes first: “the sensor measures” or “the board reads it”? (a) the sensor measures (b) the board reads it
22. 22.🔌 Is a speaker an input or an output for a microcontroller? (a) output (b) input
23. 23.⏱️ A program says “wait 6750 ms”. How many seconds is that? =
24. 24.Which of these gives us electricity? (a) a computer (b) an air conditioner (c) a generator (d) a mobile phone
25. 25.💡 3 identical bulbs are joined in parallel across a 3 V battery (ideal wires). How many volts does each bulb get? =
26. 26.True or false: “compare with a limit” is the process. (a) False (b) True
27. 27.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) wire (b) switch (c) cell (d) LED
28. 28.⚠️ Which power source should children use for electronics projects? (a) a wall socket (b) an inverter socket (c) a mains extension board (d) a small battery pack
29. 29.🔺 A current of 20 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
30. 30.🔁 count = 5
    while (count < 25) { count = count + 4 }
    How many times does the loop run?
31. 31.True or false: two or more cell symbols is the symbol for a motor. (a) False (b) True
32. 32.📏 Which unit measures resistance? (a) ohm (Ω) (b) volt (V) (c) ampere (A) (d) watt (W)
33. 33.💡 2 identical bulbs are joined in series with a 2 V battery (ideal wires). How many volts does each bulb get? =
34. 34.True or false: “own switch for each bulb” is true of a series circuit. (a) False (b) True
35. 35.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 41 °C. What is shown? (a) Hot (b) Warm (c) Cool
36. 36.Which drawing is the symbol for a resistor? (a) two equal parallel lines (b) a small empty box (c) triangle, bar and arrows (d) triangle against a bar
37. 37.🔍 Which is the odd one out? (a) touch a fallen wire (b) use mains for a project (c) touch a switch when wet (d) fly kites in open fields
38. 38.🔍 Which sensor would you use to close a window in rain? (a) a gas sensor (b) a temperature sensor (c) a rain sensor (d) a sound sensor
39. 39.🔋 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)? =
40. 40.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open

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