Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 441 · 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.📶 Digital or analog: a door: open or shut? (a) analog (b) digital
2. 2.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V ÷ R (c) I = R ÷ V (d) I = V × R
3. 3.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
4. 4.⚠️ Is it safe to climb an electric pole? (a) safe (b) not safe
5. 5.⚡ What does a night lamp mainly change electricity into? (a) sound (b) movement (c) heat (d) light
6. 6.Which of these is the input? (a) a light level reading (b) compare with a limit (c) the pump turns on (d) check if temp > 30
7. 7.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) never (c) only when both are OFF (d) only when both are ON
8. 8.🔍 Which is the odd one out? (a) a night lamp (b) a tube light (c) an LED lamp (d) an electric kettle
9. 9.True or false: the voltmeter measures current. (a) False (b) True
10. 10.💡 5 identical bulbs are joined in series with a 15 V battery (ideal wires). How many volts does each bulb get? =
11. 11.🔍 Which is the odd one out? (a) turn off unused gadgets (b) share only needed data (c) keep factory passwords (d) read app permissions
12. 12.🔐 Why install updates on IoT devices? (a) they make it heavier (b) they change the colour (c) they delete the Wi-Fi (d) they fix security holes
13. 13.💡 5 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
14. 14.What does an LDR do? (a) is a resistance knob (b) glows using little power (c) senses how bright it is (d) makes a beeping sound
15. 15.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 840 Ω resistor? (a) yellow-grey-brown (b) grey-yellow-black (c) grey-yellow-red (d) grey-yellow-brown
16. 16.🧮 A 330 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
17. 17.🔌 A gap of dry air between two wires acts as … (a) a switch that is ON (b) a conductor (c) an insulator (d) a cell
18. 18.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in parallel (c) in series (d) by Wi-Fi
19. 19.📏 In the water-pipe picture of a circuit, current is like … (a) a narrow pipe (b) the water pressure (c) the flow of water (d) the pipe colour
20. 20.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 HIGH
    set pin 8 HIGH
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
21. 21.True or false: “a break stops every bulb” is true of a series circuit. (a) True (b) False
22. 22.Which job is done by the voltage regulator? (a) connect sensors and LEDs (b) keeps the voltage steady (c) restarts the program (d) brings power and code
23. 23.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
24. 24.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) battery (b) resistor (c) diode (d) capacitor
25. 25.Which of these is the output? (a) count button presses (b) a light level reading (c) the fan starts (d) a button press
26. 26.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
27. 27.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
28. 28.🧾 A family uses 50 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
29. 29.🔘 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 ON and C is ON. Does the bulb glow? (a) Yes (b) No
30. 30.True or false: a paper strip is a conductor. (a) True (b) False
31. 31.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
32. 32.🔁 count = 4
    while (count < 20) { count = count + 4 }
    How many times does the loop run?
33. 33.🌈 A resistor has the colour bands red, green, orange. What is its value (in ohms)?
34. 34.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3.5 V supply. What current flows (in mA)?
35. 35.True or false: a laptop needs much more power. (a) True (b) False
36. 36.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is OFF, C is OFF and D is OFF. Does the bulb glow? (a) No (b) Yes
37. 37.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
38. 38.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 12 °C. What is shown? (a) Warm (b) Cool (c) Hot
39. 39.🔍 Which is the odd one out? (a) leave fridge door open (b) use daylight to read (c) close the fridge quickly (d) use LED lamps
40. 40.🔌 Is a speaker an input or an output for a microcontroller? (a) input (b) output

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