Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 858 · 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.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 150 ms }
   How many times does the LED blink in 3 seconds?
2. 2.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 7 HIGH
   set pin 8 HIGH
   set pin 8 HIGH
   Is the LED ON or OFF at the end? (a) ON (b) OFF
3. 3.Which job is done by the USB port? (a) shows the board is on (b) keeps the voltage steady (c) runs the program (d) brings power and code
4. 4.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
5. 5.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
6. 6.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) parallel (b) series
7. 7.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
8. 8.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) their sum (c) always zero (d) less than either one
9. 9.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
10. 10.Which of these mainly makes sound? (a) a mixer grinder (b) a tube light (c) a loudspeaker (d) a rice cooker
11. 11.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 450 ms }
    How many milliseconds does one blink (ON + OFF) take?
12. 12.True or false: to start a fan when hot, use a temperature sensor. (a) True (b) False
13. 13.💡 A battery lights 4 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
14. 14.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V + R (c) I = V × R (d) I = V ÷ R
15. 15.🔌 Which part of a screwdriver should an electrician hold? (a) the plastic handle (b) the steel shaft (c) the metal tip (d) the bare end
16. 16.Which of these is an insulator? (a) a graphite rod (b) a wooden stick (c) aluminium foil (d) a steel spoon
17. 17.🔁 repeat 3 times { repeat 6 times { beep } }
    How many beeps are there?
18. 18.True or false: the voltmeter is joined across a part. (a) True (b) False
19. 19.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is ON, B is OFF and C is OFF. Does the bulb glow? (a) Yes (b) No
20. 20.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a motor (c) an LED (d) a resistor
21. 21.🔁 x = 4
    repeat 3 times { x = x × 2 }
    What is x at the end?
22. 22.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 HIGH
    set pin 8 LOW
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
23. 23.True or false: a motor makes things spin. (a) False (b) True
24. 24.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
25. 25.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
26. 26.True or false: two equal parallel lines is the symbol for a capacitor. (a) False (b) True
27. 27.Which of these is measured in volts (V)? (a) power (b) how much a part resists (c) current (d) the push of a cell
28. 28.⚡ A 5 W device works on 5 V. What current does it take (in amperes)? =
29. 29.🧾 A family uses 160 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
30. 30.True or false: a potentiometer is a resistance knob. (a) True (b) False
31. 31.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 25) { show “Warm” } else { show “Cool” }
    The temperature is 35 °C. What is shown? (a) Warm (b) Cool (c) Hot
32. 32.🔍 Which is the odd one out? (a) stay away from pylons (b) fly kites in open fields (c) stop if a part gets hot (d) poke things in a socket
33. 33.🔍 Which sensor would you use to make a parking alarm? (a) a distance sensor (b) a motion sensor (c) a sound sensor (d) a soil moisture sensor
34. 34.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) takes 1 away (d) sets count to 1
35. 35.🔘 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 ON and D is ON. Does the bulb glow? (a) No (b) Yes
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 ON and C is OFF. Does the bulb glow? (a) Yes (b) No
37. 37.💡 3 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
38. 38.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) none (c) two (d) one
39. 39.True or false: a room heater mainly gives out heat. (a) False (b) True
40. 40.Which of these saves electricity? (a) leave the TV on standby (b) switch off empty rooms (c) leave fridge door open (d) iron one shirt at a time

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