Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 536 · 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.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) the sensor measures (b) the app shows it (c) it is sent by Wi-Fi (d) the board reads it
2. 2.🔺 A current of 0.2 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
3. 3.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 310 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
4. 4.🔋 8 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
5. 5.🔍 Which sensor would you use to make a parking alarm? (a) a soil moisture sensor (b) a rain sensor (c) a distance sensor (d) a sound sensor
6. 6.🔺 A current of 0.25 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
7. 7.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) stores a value (d) blinks an LED
8. 8.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
9. 9.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is OFF, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
10. 10.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the process (b) the input (c) the battery (d) the output
11. 11.🤖 Does a microwave oven usually have a microcontroller inside? (a) No (b) Yes
12. 12.🔍 Which sensor would you use to warn of a gas leak? (a) a gas sensor (b) a temperature sensor (c) a rain sensor (d) a distance sensor
13. 13.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 25 % (d) 5 %
14. 14.Which of these gives us electricity? (a) a generator (b) an air conditioner (c) a water pump (d) a washing machine
15. 15.True or false: a hand pump has no microcontroller inside. (a) False (b) True
16. 16.🌐 In an IoT system, which part measures the real world? (a) sensor (b) actuator (c) microcontroller (d) phone app
17. 17.Which drawing is the symbol for a motor? (a) a dot where wires meet (b) one tall, one short bar (c) a circle with M inside (d) a circle with an X in it
18. 18.What does a push button do? (a) closes when tipped over (b) springs back when let go (c) stays where you flip it (d) slides side to side
19. 19.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
20. 20.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) the same voltage (c) no voltage (d) half the voltage
21. 21.⏱️ repeat 3 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
22. 22.🔌 Is a light sensor an input or an output for a microcontroller? (a) output (b) input
23. 23.🧮 Resistors of 22 Ω, 22 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
24. 24.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
25. 25.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
26. 26.True or false: “each gets the full volts” is true of a parallel circuit. (a) False (b) True
27. 27.Which of these is a conductor? (a) a rubber eraser (b) a metal paper clip (c) a ceramic cup (d) a rubber band
28. 28.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V ÷ R (c) I = V + R (d) I = R ÷ V
29. 29.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
30. 30.True or false: on an LED, the leg by the flat edge is the anode (+). (a) True (b) False
31. 31.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) both lines (c) the shorter line (d) the longer line
32. 32.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I + R (d) V = I × R
33. 33.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
34. 34.Which job is done by the pins? (a) keeps the voltage steady (b) brings power and code (c) shows the board is on (d) connect sensors and LEDs
35. 35.💡 An LED is joined to a 5 V battery through a 470 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) lights up (b) does not light (c) may burn out
36. 36.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
37. 37.🔍 Which is the odd one out? (a) fly kites in open fields (b) use a cable with cuts (c) keep drinks far away (d) build with an adult near
38. 38.🔍 Which is the odd one out? (a) leave the TV on standby (b) iron one shirt at a time (c) close the fridge quickly (d) run fans in empty rooms
39. 39.🌐 A soil sensor sends a reading to an app every 10 minutes. How many readings arrive in 2 hours?
40. 40.💡 An LED is joined to a 9 V battery through a 220 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) does not light (b) lights up (c) may burn out

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