Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 404 · 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.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) pour water on them (b) wait and watch (c) shout for an adult (d) pull them by the hand
2. 2.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 240 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
3. 3.True or false: a laptop runs many apps at once. (a) True (b) False
4. 4.Which of these is the process? (a) compare with a limit (b) an LED lights up (c) a motion sensor signal (d) an alert on the phone
5. 5.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 25 % (d) 5 %
6. 6.🔺 A current of 0.5 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
7. 7.True or false: a table fan mainly makes movement. (a) False (b) True
8. 8.🤖 if (temperature > 25) { fan ON } else { fan OFF }
   The temperature sensor reads 17 °C. What happens? (a) fan OFF (b) fan ON
9. 9.What does a push button do? (a) stays where you flip it (b) slides side to side (c) flips up or down (d) springs back when let go
10. 10.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
11. 11.🔋 Does a washing machine give electricity or use electricity? (a) uses electricity (b) gives electricity
12. 12.Which of these is safe? (a) use small battery cells (b) poke things in a socket (c) use mains for a project (d) throw cells in a fire
13. 13.🧾 A family uses 80 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
14. 14.What does an LDR do? (a) senses how bright it is (b) stores a little charge (c) blows if current is high (d) smooths a wobbly supply
15. 15.🔍 Which is the odd one out? (a) keep drinks far away (b) build with an adult near (c) climb an electric pole (d) use small battery cells
16. 16.⚡ A 3 W device works on 6 V. What current does it take (in amperes)? =
17. 17.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the plastic handle (c) the bare end (d) the metal tip
18. 18.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is ON, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
19. 19.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
20. 20.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) the length of a wire (d) energy used each second
21. 21.🔋 Does a water pump give electricity or use electricity? (a) gives electricity (b) uses electricity
22. 22.Which job needs a motor? (a) open a gate to 90° (b) beep an alarm (c) spin a robot’s wheels (d) turn to an exact angle
23. 23.🔁 x = 4
    repeat 2 times { x = x × 2 }
    What is x at the end?
24. 24.True or false: “a single current path” is true of a series circuit. (a) False (b) True
25. 25.🌐 Is a Wi-Fi smart plug an IoT device? (a) an IoT device (b) not an IoT device
26. 26.Which of these is true of a series circuit? (a) each gets the full volts (b) one out, the rest glow (c) a single current path (d) used in house wiring
27. 27.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
28. 28.Which drawing is the symbol for a resistor? (a) a plain rectangle (b) a circle with a cross (c) a circle with an X in it (d) a line lifted at a gap
29. 29.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
30. 30.🔋 What should you do with used-up cells? (a) bury them in soil (b) cut them open (c) give them for recycling (d) throw them in a fire
31. 31.📏 How many ohms (Ω) is 4.4 kΩ?
32. 32.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) it is sent by Wi-Fi (b) the app shows it (c) the sensor measures (d) the board reads it
33. 33.Which drawing is the symbol for a cell? (a) a straight line (b) triangle against a bar (c) one tall, one short bar (d) a dot where wires meet
34. 34.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
35. 35.🧩 Which component beeps for an alarm? (a) LED (b) motor (c) diode (d) buzzer
36. 36.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) their sum (c) less than either one (d) always zero
37. 37.⚠️ Is it safe to fly kites in open fields? (a) safe (b) not safe
38. 38.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
39. 39.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
40. 40.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) stay the same (d) bigger

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