Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 25 · 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.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 20 readings take?
2. 2.🧾 A family uses 60 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
3. 3.🔺 A current of 0.2 A flows when 2.4 V is joined across a resistor. What is its resistance (in ohms)?
4. 4.True or false: a circle with V inside is the symbol for a switch. (a) False (b) True
5. 5.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) False (b) True
6. 6.🧮 Two resistors in parallel give a total that is … (a) always zero (b) less than either one (c) more than either one (d) their sum
7. 7.🧩 A capacitor in a circuit can … (a) store charge briefly (b) spin a wheel (c) measure heat (d) make light
8. 8.Which job is done by the USB port? (a) connect sensors and LEDs (b) runs the program (c) keeps the voltage steady (d) brings power and code
9. 9.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) nuclear energy (c) wind energy (d) electrical energy
10. 10.Which of these uses electricity? (a) a mobile phone (b) a battery (c) a solar panel (d) a wind turbine
11. 11.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
12. 12.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the bulb is unscrewed (d) all wires are joined
13. 13.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 9 seconds?
14. 14.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) a motor (d) an LED
15. 15.🔁 repeat 3 times { repeat 2 times { beep } }
    How many beeps are there?
16. 16.What does a potentiometer do? (a) makes things spin (b) turns a fan or wheels (c) is a resistance knob (d) makes a beeping sound
17. 17.Which drawing is the symbol for a resistor? (a) triangle against a bar (b) a circle with a cross (c) triangle, bar and arrows (d) a small empty box
18. 18.🔋 How many 1.2 V cells must be joined in series to give 7.2 V?
19. 19.True or false: a buzzer beeps for an alarm. (a) False (b) True
20. 20.What does the actuator do? (a) acts on a command (b) stores data online (c) carries the data (d) shows data to you
21. 21.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
22. 22.⚡ A 1.2 W device works on 12 V. What current does it take (in amperes)? =
23. 23.True or false: a toy robot has no microcontroller inside. (a) False (b) True
24. 24.⚡ A 13.5 W device works on 9 V. What current does it take (in amperes)? =
25. 25.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 5 is taken out of its holder. Does bulb 3 glow? (a) No (b) Yes
26. 26.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = R ÷ V (c) I = V × R (d) I = V + R
27. 27.🗺️ Before building a project, what should you write down first? (a) inputs and outputs (b) the box colour (c) nothing at all (d) the final price
28. 28.📏 How many milliamperes (mA) make 1 ampere? (a) 10 (b) 100 (c) 60 (d) 1000
29. 29.Which of these is measured in volts (V)? (a) voltage (b) power (c) current (d) how much a part resists
30. 30.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) when either is ON (c) when both are ON (d) never
31. 31.🧮 A 68 Ω resistor is joined in series with two equal 1000 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
32. 32.🔺 A 16 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
33. 33.⚡ A 6 W device works on 12 V. What current does it take (in amperes)? =
34. 34.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 33 Ω resistor? (a) orange-yellow-black (b) yellow-orange-black (c) orange-orange-black (d) orange-orange-brown
35. 35.True or false: a motor makes a beeping sound. (a) True (b) False
36. 36.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 1800 ms }
    How many times does the LED blink in 10 seconds?
37. 37.🔺 A current of 20 mA flows when 4.4 V is joined across a resistor. What is its resistance (in ohms)?
38. 38.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
39. 39.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
40. 40.🔘 When a switch is ON, the circuit is … (a) broken (b) cut (c) open (d) closed

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