Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 751 · 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 drawing is the symbol for a voltmeter? (a) a line lifted at a gap (b) a circle with a cross (c) a circle with V inside (d) triangle against a bar
2. 2.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) a cell is taken out (d) all wires are joined
3. 3.Which of these is measured in watts (W)? (a) the flow of charge (b) voltage (c) resistance (d) power
4. 4.Which of these wastes electricity? (a) use daylight to read (b) unplug idle chargers (c) use old filament bulbs (d) close the fridge quickly
5. 5.🔌 A gap of dry air between two wires acts as … (a) a conductor (b) a switch that is ON (c) an insulator (d) a cell
6. 6.🔺 A current of 0.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
7. 7.🔺 A current of 0.2 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
8. 8.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
9. 9.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) a Wi-Fi weather station (c) an app-controlled bulb (d) a battery torch
10. 10.True or false: “used in house wiring” is true of a series circuit. (a) False (b) True
11. 11.Which job needs a sound sensor? (a) keep an incubator warm (b) start a fan when hot (c) switch on with a clap (d) make a parking alarm
12. 12.🔍 Which is the odd one out? (a) use a cable with cuts (b) fly a kite near wires (c) throw cells in a fire (d) build with an adult near
13. 13.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
14. 14.True or false: a reed switch closes near a magnet. (a) False (b) True
15. 15.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 170 readings take?
16. 16.🔁 What does a variable do in a program? (a) blinks an LED (b) joins two wires (c) stores a value (d) measures light
17. 17.Which job needs a gas sensor? (a) warn of a gas leak (b) measure classroom noise (c) start a fan when hot (d) switch on lamps at dusk
18. 18.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) a bigger voltage (c) the same voltage (d) a smaller voltage
19. 19.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 10 °C. What is shown? (a) Warm (b) Hot (c) Cool
20. 20.📏 How many watts (W) is 0.9 kW?
21. 21.🔘 Which kind of switch closes when tipped over? (a) a reed switch (b) a push button (c) a tilt switch (d) a toggle switch
22. 22.🔘 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 OFF and C is ON. Does the bulb glow? (a) No (b) Yes
23. 23.🔺 A current of 50 mA flows when 11 V is joined across a resistor. What is its resistance (in ohms)?
24. 24.Which of these is a good habit? (a) install software updates (b) ignore update messages (c) keep factory passwords (d) accept every permission
25. 25.Which job is done by the USB port? (a) connect sensors and LEDs (b) restarts the program (c) brings power and code (d) runs the program
26. 26.🔺 A 1.2 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
27. 27.⏱️ loop forever { LED ON; wait 500 ms; LED OFF; wait 500 ms }
    How many times does the LED blink in 3 seconds?
28. 28.⏱️ loop forever { LED ON; wait 850 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 5 seconds?
29. 29.🌈 A resistor has the colour bands red, brown, yellow. What is its value in kilo-ohms (kΩ)? =
30. 30.True or false: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
31. 31.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
32. 32.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
33. 33.🌈 In the resistor colour code, which number does black stand for?
34. 34.🧩 A capacitor in a circuit can … (a) measure heat (b) make light (c) store charge briefly (d) spin a wheel
35. 35.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) output (b) process (c) input
36. 36.Which of these is measured in amperes (A)? (a) current (b) energy used each second (c) resistance (d) how much a part resists
37. 37.🧮 Resistors of 47 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
38. 38.🌐 In an IoT system, which part acts on a command? (a) microcontroller (b) Wi-Fi (c) sensor (d) actuator
39. 39.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
40. 40.True or false: to turn off unused gadgets is a risky habit. (a) True (b) False

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