Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 891 · 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 metal is used for most electric wires at home? (a) copper (b) plastic (c) glass (d) rubber
2. 2.Which of these is an output? (a) a light sensor (b) a push button (c) a keypad (d) an LED
3. 3.Which of these is a risky habit? (a) set a strong password (b) log out of shared phones (c) reuse one password (d) install software updates
4. 4.🔍 Which is the odd one out? (a) an alert on the phone (b) an LED lights up (c) a buzzer beeps (d) count button presses
5. 5.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
6. 6.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) a bigger voltage (c) a smaller voltage (d) no voltage
7. 7.🤖 Does a spinning top usually have a microcontroller inside? (a) No (b) Yes
8. 8.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 270 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
9. 9.⏱️ A program says “wait 7500 ms”. How many seconds is that? =
10. 10.🧾 A family uses 100 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
11. 11.🧮 Resistors of 10 Ω, 50 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
12. 12.True or false: to log out of shared phones is a risky habit. (a) False (b) True
13. 13.What does the phone app do? (a) reads values, decides (b) shows data to you (c) acts on a command (d) carries the data
14. 14.True or false: to reuse one password is a good habit. (a) False (b) True
15. 15.True or false: triangle, bar and arrows is the symbol for a diode. (a) True (b) False
16. 16.Which drawing is the symbol for a wire? (a) a circle with M inside (b) a straight line (c) a circle with a cross (d) two or more cell symbols
17. 17.🔐 Is it a good or a risky habit to reuse one password? (a) good habit (b) risky habit
18. 18.⚠️ Is it safe to build with an adult near? (a) not safe (b) safe
19. 19.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) No (b) Yes
20. 20.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) zero (c) bigger (d) smaller
21. 21.🧩 Which component is a resistance knob? (a) LDR (b) thermistor (c) potentiometer (d) motor
22. 22.🔍 Which is the odd one out? (a) set up with a parent (b) tap unknown app links (c) turn off unused gadgets (d) share only needed data
23. 23.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) both of them (c) only one (d) none
24. 24.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 84. What happens? (a) green LED ON (b) red LED ON
25. 25.📏 Which unit measures energy used each second? (a) ohm (Ω) (b) volt (V) (c) ampere (A) (d) watt (W)
26. 26.True or false: a paper strip is a conductor. (a) False (b) True
27. 27.🔺 A current of 1.5 A flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
28. 28.🔍 Which sensor would you use to stop a robot near walls? (a) a distance sensor (b) a light sensor (c) a sound sensor (d) a soil moisture sensor
29. 29.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
30. 30.🔌 Is a water pump an input or an output for a microcontroller? (a) output (b) input
31. 31.🔺 A 5 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
32. 32.True or false: a tube light mainly gives out light. (a) False (b) True
33. 33.Which drawing is the symbol for a cell? (a) many long-short pairs (b) a circle with A inside (c) a dot where wires meet (d) one tall, one short bar
34. 34.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
35. 35.⚠️ About how many volts do home sockets in India supply? (a) 1.5 V (b) 12 V (c) 230 V (d) 9 V
36. 36.🌈 A resistor has the colour bands green, yellow, red. What is its value in kilo-ohms (kΩ)? =
37. 37.True or false: “the room temperature” is a digital signal. (a) True (b) False
38. 38.🔺 A 12 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
39. 39.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) it is sent by Wi-Fi (b) the board reads it (c) the app shows it (d) the sensor measures
40. 40.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = I ÷ V (d) P = V ÷ I

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