Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 278 · 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.💡 An LED is joined to a 9 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) does not light (c) lights up
2. 2.Which of these mainly gives out heat? (a) an electric kettle (b) a table fan (c) a mixer grinder (d) a loudspeaker
3. 3.⏱️ How many milliseconds is a wait of 0.5 seconds?
4. 4.Which of these is true of a series circuit? (a) used in house wiring (b) each gets the full volts (c) many paths for current (d) bulbs share the voltage
5. 5.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = V + I (d) P = I ÷ V
6. 6.🧾 A family uses 90 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
7. 7.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
8. 8.🌈 In the resistor colour code, which number does yellow stand for?
9. 9.Which of these is measured in volts (V)? (a) resistance (b) how much a part resists (c) voltage (d) the flow of charge
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 plastic straw. Does the bulb glow? (a) Yes (b) No
11. 11.🧮 Resistors of 47 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
12. 12.🔢 To plan an electronics project, which is the LAST step? (a) test it and fix it (b) list inputs and outputs (c) build it with an adult (d) pick a problem to solve
13. 13.🔋 5 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
14. 14.True or false: “a single current path” is true of a series circuit. (a) True (b) False
15. 15.🔌 Is a turning knob an input or an output for a microcontroller? (a) output (b) input
16. 16.🔋 How many 2 V cells must be joined in series to give 14 V?
17. 17.🌐 In an IoT system, which part reads values, decides? (a) Wi-Fi (b) actuator (c) microcontroller (d) cloud server
18. 18.📶 A pin set LOW gives about … (a) 5 V (b) 0 V (c) 9 V (d) 1.5 V
19. 19.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) energy used each second (d) the colour of light
20. 20.True or false: a toggle switch closes near a magnet. (a) False (b) True
21. 21.Which of these is true of a series circuit? (a) each gets the full volts (b) one bulb out, all go out (c) own switch for each bulb (d) many paths for current
22. 22.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
23. 23.🔺 A current of 10 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
24. 24.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 90 readings take?
25. 25.True or false: to water a dry plant, use a soil moisture sensor. (a) False (b) True
26. 26.Which of these gives us electricity? (a) a washing machine (b) a battery (c) a water pump (d) an air conditioner
27. 27.Which of these is the input? (a) compare with a limit (b) the pump turns on (c) the fan starts (d) a light level reading
28. 28.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
29. 29.🔍 Which is the odd one out? (a) a pencil sharpener (b) a paper calendar (c) an app-controlled bulb (d) a plain table fan
30. 30.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
31. 31.🔦 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 steel spoon. Does the bulb glow? (a) No (b) Yes
32. 32.🔺 A current of 20 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🔍 Which is the odd one out? (a) a battery torch (b) a plain wall switch (c) a paper calendar (d) a Wi-Fi weather station
34. 34.True or false: triangle, bar and arrows is the symbol for a switch. (a) True (b) False
35. 35.⚡ A device works on 5 V and takes 0.1 A. What is its power (in watts)? =
36. 36.True or false: to fly a kite near wires is not safe. (a) True (b) False
37. 37.🗺️ Before building a project, what should you write down first? (a) nothing at all (b) inputs and outputs (c) the final price (d) the box colour
38. 38.🔁 repeat 4 times { repeat 5 times { beep } }
    How many beeps are there?
39. 39.Which job needs a display? (a) spin a robot’s wheels (b) show the temperature (c) open a gate to 90° (d) turn to an exact angle
40. 40.Which of these is an insulator? (a) a copper wire (b) a metal paper clip (c) aluminium foil (d) a woollen thread

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