Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 247 · 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.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) both lines (c) the shorter line (d) neither line
2. 2.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a wire is cut (d) all wires are joined
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
4. 4.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) pull them by the hand (b) wait and watch (c) shout for an adult (d) pour water on them
5. 5.True or false: a circle with a cross is the symbol for a bulb. (a) True (b) False
6. 6.🧮 An 8.5 V battery is joined to 12 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
7. 7.📏 How many amperes (A) is 410 mA? =
8. 8.⚡ A 0.75 W device works on 3 V. What current does it take (in amperes)? =
9. 9.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 300 ms }
   How many milliseconds does one blink (ON + OFF) take?
10. 10.🌈 A resistor has the colour bands brown, yellow, orange. What is its value (in ohms)?
11. 11.Which drawing is the symbol for an ammeter? (a) a circle with V inside (b) a circle with A inside (c) a straight line (d) a line lifted at a gap
12. 12.🧾 A family uses 100 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
13. 13.🔍 Which is the odd one out? (a) a plastic ruler (b) a brass key (c) an iron nail (d) a steel coin
14. 14.🔌 Is a buzzer an input or an output for a microcontroller? (a) input (b) output
15. 15.🔺 A current of 25 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
16. 16.⚠️ Is it safe to climb an electric pole? (a) safe (b) not safe
17. 17.True or false: the ammeter is joined in series. (a) True (b) False
18. 18.🤖 “if (A AND B)” is true when … (a) only B is true (b) only A is true (c) both A and B are true (d) both are false
19. 19.Which of these is a conductor? (a) a safety pin (b) a woollen thread (c) a rubber eraser (d) a plastic ruler
20. 20.🔍 Which is the odd one out? (a) a light level reading (b) a motion sensor signal (c) a soil moisture reading (d) the fan starts
21. 21.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
22. 22.🔍 Which sensor would you use to keep an incubator warm? (a) a distance sensor (b) a temperature sensor (c) a sound sensor (d) a light sensor
23. 23.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 607. What happens? (a) lamp OFF (b) lamp ON
24. 24.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
25. 25.⏱️ loop forever { LED ON; wait 950 ms; LED OFF; wait 1000 ms }
    How many milliseconds does one blink (ON + OFF) take?
26. 26.🔍 Which is the odd one out? (a) a cotton thread (b) a ceramic cup (c) a glass marble (d) an iron nail
27. 27.🔍 Which is the odd one out? (a) close the fridge quickly (b) use old filament bulbs (c) set the AC to 24 °C (d) unplug idle chargers
28. 28.💡 3 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
29. 29.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) True (b) False
30. 30.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) waits 500 seconds (c) turns the LED off (d) blinks 500 times
31. 31.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
32. 32.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I ÷ R (c) V = R ÷ I (d) V = I + R
33. 33.🔋 2 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
34. 34.🧮 A 47 Ω resistor is joined in series with two equal 220 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
35. 35.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 170 readings take?
36. 36.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is OFF and C is ON. Does the bulb glow? (a) No (b) Yes
37. 37.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) adds 1 to count (c) takes 1 away (d) prints 1
38. 38.🔍 Which is the odd one out? (a) a loudspeaker (b) a buzzer (c) an LED lamp (d) a siren
39. 39.🔍 Which is the odd one out? (a) an LED (b) a light sensor (c) a push button (d) a temperature sensor
40. 40.🧩 Which component turns a fan or wheels? (a) fuse (b) LED (c) resistor (d) motor

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