Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 794 · 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.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
2. 2.True or false: a rice cooker mainly makes sound. (a) False (b) True
3. 3.⚡ A device works on 9 V and takes 0.25 A. What is its power (in watts)? =
4. 4.🌐 Is a fitness band with app an IoT device? (a) not an IoT device (b) an IoT device
5. 5.📏 How many kilowatts (kW) is 1450 W? =
6. 6.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
7. 7.Which of these is safe? (a) touch a fallen wire (b) keep drinks far away (c) throw cells in a fire (d) touch a switch when wet
8. 8.True or false: the flow of charge is measured in amperes (A). (a) False (b) True
9. 9.Which of these is safe? (a) dry your hands first (b) touch a fallen wire (c) open a phone charger (d) use a cable with cuts
10. 10.🔦 A circuit has a new 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 copper wire. Does the bulb glow? (a) No (b) Yes
11. 11.📏 How many watts (W) is 4.6 kW?
12. 12.🔍 Which is the odd one out? (a) touch a switch when wet (b) touch a fallen wire (c) build with an adult near (d) use a cable with cuts
13. 13.🔍 Which is the odd one out? (a) fly a kite near wires (b) open a phone charger (c) take cells out after use (d) throw cells in a fire
14. 14.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
15. 15.True or false: “one out, the rest glow” is true of a series circuit. (a) False (b) True
16. 16.🌈 A resistor has the colour bands green, orange, black. What is its value (in ohms)?
17. 17.Which of these mainly makes movement? (a) an exhaust fan (b) an LED lamp (c) an electric kettle (d) a doorbell
18. 18.Which of these is the output? (a) an alert on the phone (b) a light level reading (c) a button press (d) a soil moisture reading
19. 19.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) resistor (b) ammeter (c) battery (d) bulb
20. 20.🔍 A distance sensor sends a sound pulse and hears the echo 19 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
21. 21.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
22. 22.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
23. 23.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
24. 24.🔺 A current of 25 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
25. 25.True or false: to water a dry plant, use a soil moisture sensor. (a) False (b) True
26. 26.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
27. 27.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a copper wire across the gap. Does the bulb glow? (a) Yes (b) No
28. 28.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 190 readings take?
29. 29.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it lights brighter (c) it does not light (d) it changes colour
30. 30.Which of these is a good habit? (a) set up with a parent (b) tap unknown app links (c) post your live location (d) share camera links
31. 31.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) both parts (c) neither part (d) the else part
32. 32.🔍 Which is the odd one out? (a) count button presses (b) check if temp > 30 (c) the fan starts (d) decide if soil is dry
33. 33.🧾 A family uses 130 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
34. 34.True or false: a circle with M inside is the symbol for a motor. (a) False (b) True
35. 35.What does the microcontroller do? (a) stores data online (b) acts on a command (c) shows data to you (d) reads values, decides
36. 36.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
37. 37.⚡ A 4.8 W device works on 24 V. What current does it take (in amperes)? =
38. 38.Which of these is true of a parallel circuit? (a) own switch for each bulb (b) a single current path (c) a break stops every bulb (d) one bulb out, all go out
39. 39.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 370 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
40. 40.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “test it and fix it”? (a) pick a problem to solve (b) test it and fix it

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