Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 56 · 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.🔍 Which is the odd one out? (a) a safety pin (b) a metal paper clip (c) a glass marble (d) a graphite rod
2. 2.🤖 if (temperature > 32) { fan ON } else { fan OFF }
   The temperature sensor reads 34 °C. What happens? (a) fan ON (b) fan OFF
3. 3.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
4. 4.📏 Which unit measures current? (a) ampere (A) (b) ohm (Ω) (c) volt (V) (d) watt (W)
5. 5.⏱️ How many milliseconds is a wait of 4.7 seconds?
6. 6.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
7. 7.🔺 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
8. 8.True or false: the push of a cell is measured in watts (W). (a) True (b) False
9. 9.🔍 Which is the odd one out? (a) stay away from pylons (b) keep drinks far away (c) use mains for a project (d) fly kites in open fields
10. 10.True or false: “how loud a sound is” is a digital signal. (a) False (b) True
11. 11.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
12. 12.True or false: “used in house wiring” is true of a series circuit. (a) True (b) False
13. 13.Which of these gives us electricity? (a) a water pump (b) a television (c) a solar panel (d) a washing machine
14. 14.🧩 Which component turns a fan or wheels? (a) LED (b) buzzer (c) diode (d) motor
15. 15.Which job needs a pump? (a) show a status light (b) open a gate to 90° (c) move water to plants (d) show the temperature
16. 16.🧮 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
17. 17.🧩 Which component blows if current is high? (a) diode (b) capacitor (c) LDR (d) fuse
18. 18.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) Yes (b) No
19. 19.Which of these is measured in amperes (A)? (a) resistance (b) current (c) how much a part resists (d) voltage
20. 20.⚡ A 3 W device works on 1.5 V. What current does it take (in amperes)? =
21. 21.Which of these mainly gives out heat? (a) a tube light (b) a doorbell (c) an electric kettle (d) a table fan
22. 22.🔺 A current of 0.25 A flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?
23. 23.🔺 A current of 0.2 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
24. 24.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is OFF (d) a wire has come loose
25. 25.🔘 A bulb and a cell are joined through 6 switches on 6 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
26. 26.True or false: to open blinds at sunrise, use a light sensor. (a) False (b) True
27. 27.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
28. 28.🔺 A current of 0.1 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
29. 29.Which of these saves electricity? (a) use old filament bulbs (b) run fans in empty rooms (c) use daylight to read (d) leave the TV on standby
30. 30.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
31. 31.🔐 Is it a good or a risky habit to install software updates? (a) risky habit (b) good habit
32. 32.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a plug top (b) a fuse or MCB (c) a bulb (d) a long wire
33. 33.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
34. 34.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) capacitor (b) LED (c) cell (d) battery
35. 35.🗺️ In an input → process → output plan, is “check if temp > 30” the input, the process or the output? (a) process (b) input (c) output
36. 36.⏱️ repeat 2 times { buzzer ON; wait 900 ms; buzzer OFF; wait 900 ms }
    How many milliseconds does this take in all?
37. 37.🧾 A family uses 190 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
38. 38.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
39. 39.🤖 What is a microcontroller? (a) a big desktop computer (b) a type of battery (c) a kind of bulb (d) a computer on one chip
40. 40.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?

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