Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 786 · 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 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
2. 2.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
3. 3.🧾 A family uses 190 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
4. 4.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
5. 5.💡 In a series circuit, how many paths does the current have? (a) one (b) one for each bulb (c) none (d) two
6. 6.🔋 Cells joined + to − in a row (series) give … (a) a smaller voltage (b) no voltage (c) a bigger voltage (d) the same voltage
7. 7.🧮 Resistors of 150 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?
8. 8.🔍 Which sensor would you use to stop a robot near walls? (a) a motion sensor (b) a gas sensor (c) a light sensor (d) a distance sensor
9. 9.True or false: a circle with V inside is the symbol for a voltmeter. (a) True (b) False
10. 10.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) so all go off together (d) each gets full voltage
11. 11.Which of these is a good habit? (a) tap unknown app links (b) accept every permission (c) turn off unused gadgets (d) keep factory passwords
12. 12.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
13. 13.🔘 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 ON and C is ON. Does the bulb glow? (a) Yes (b) No
14. 14.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 30 readings take?
15. 15.What does a tilt switch do? (a) closes when tipped over (b) flips up or down (c) works only while pressed (d) springs back when let go
16. 16.🔘 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
17. 17.Which of these uses electricity? (a) a power station (b) a generator (c) a solar panel (d) a television
18. 18.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
19. 19.🔐 Is it a good or a risky habit to cover unused cameras? (a) good habit (b) risky habit
20. 20.⏱️ loop forever { LED ON; wait 550 ms; LED OFF; wait 450 ms }
    How many milliseconds does one blink (ON + OFF) take?
21. 21.🔌 Is a motion sensor an input or an output for a microcontroller? (a) output (b) input
22. 22.🔺 A current of 25 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
23. 23.💡 An LED is joined to a 6 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) lights up (b) does not light (c) may burn out
24. 24.True or false: two equal parallel lines is the symbol for a bulb. (a) False (b) True
25. 25.📶 Digital or analog: a tilt switch: on or off? (a) digital (b) analog
26. 26.True or false: to climb an electric pole is safe. (a) True (b) False
27. 27.🔋 Identical cells side by side (in parallel) give … (a) half the voltage (b) the same voltage (c) no voltage (d) double the voltage
28. 28.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is OFF, B is OFF and C is ON. Does the bulb glow? (a) No (b) Yes
29. 29.📏 How many milliamperes (mA) make 1 ampere? (a) 60 (b) 10 (c) 100 (d) 1000
30. 30.True or false: a potentiometer is a resistance knob. (a) False (b) True
31. 31.True or false: to run fans in empty rooms wastes electricity. (a) True (b) False
32. 32.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 100 (c) 10 (d) 1000
33. 33.Which of these is a good habit? (a) post your live location (b) share only needed data (c) tap unknown app links (d) keep factory passwords
34. 34.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity
35. 35.Which of these saves electricity? (a) use daylight to read (b) iron one shirt at a time (c) leave fridge door open (d) use old filament bulbs
36. 36.True or false: a cotton thread is an insulator. (a) True (b) False
37. 37.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a glass marble across the gap. Does the bulb glow? (a) No (b) Yes
38. 38.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
39. 39.🔘 Which kind of switch closes near a magnet? (a) a push button (b) a toggle switch (c) a slide switch (d) a reed switch
40. 40.📏 How many ohms (Ω) is 1.7 kΩ?

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