Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 754 · 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 colour bands (1st digit, 2nd digit, multiplier) mark a 27000 Ω resistor? (a) violet-red-orange (b) red-violet-orange (c) red-violet-yellow (d) red-violet-red
2. 2.📏 Which unit measures voltage? (a) watt (W) (b) ohm (Ω) (c) ampere (A) (d) volt (V)
3. 3.Which of these is measured in volts (V)? (a) resistance (b) energy used each second (c) the push of a cell (d) power
4. 4.🧾 A family uses 150 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
5. 5.🤖 “if (A AND B)” is true when … (a) only A is true (b) both are false (c) only B is true (d) both A and B are true
6. 6.🔌 Most metals are good … (a) conductors (b) insulators (c) batteries (d) magnets only
7. 7.🔍 Which is the odd one out? (a) a servo motor (b) a small display (c) a motor (d) a temperature sensor
8. 8.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is OFF, C is OFF and D is OFF. Does the bulb glow? (a) Yes (b) No
9. 9.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
10. 10.Which of these is an insulator? (a) a ceramic cup (b) a graphite rod (c) a metal paper clip (d) a brass key
11. 11.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
12. 12.⚠️ Who should be with you when you build a circuit? (a) nobody (b) a stranger online (c) a younger child (d) a trusted adult
13. 13.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 4 seconds?
14. 14.Which of these is a risky habit? (a) read app permissions (b) set up with a parent (c) cover unused cameras (d) share camera links
15. 15.Which drawing is the symbol for a resistor? (a) a circle with M inside (b) a circle with an X in it (c) two or more cell symbols (d) a small empty box
16. 16.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) smaller (c) zero (d) bigger
17. 17.🔐 Is it a good or a risky habit to set a strong password? (a) risky habit (b) good habit
18. 18.🧮 A 220 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
19. 19.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
20. 20.True or false: many long-short pairs is the symbol for a junction. (a) True (b) False
21. 21.🔁 total = 0
    for i = 1 to 9 { total = total + i }
    What is total at the end?
22. 22.🔍 Which sensor would you use to switch on lamps at dusk? (a) a temperature sensor (b) a light sensor (c) a sound sensor (d) a distance sensor
23. 23.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
24. 24.Which of these is an input? (a) a motion sensor (b) an LED (c) a motor (d) a small display
25. 25.🔋 Identical cells side by side (in parallel) give … (a) no voltage (b) double the voltage (c) half the voltage (d) the same voltage
26. 26.📏 Which unit measures the push of a cell? (a) ohm (Ω) (b) volt (V) (c) watt (W) (d) ampere (A)
27. 27.True or false: to cover unused cameras is a good habit. (a) False (b) True
28. 28.Which job needs a display? (a) spin a robot’s wheels (b) show the temperature (c) move water to plants (d) beep an alarm
29. 29.Which of these is a good habit? (a) ignore update messages (b) post your live location (c) set up with a parent (d) tap unknown app links
30. 30.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) both of them (c) none (d) only one
31. 31.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
32. 32.🧮 Three equal 75 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
33. 33.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) more than either one (d) less than either one
34. 34.🔁 count = 1
    repeat 6 times { count = count + 7 }
    What is count at the end?
35. 35.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
36. 36.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber band across the gap. Does the bulb glow? (a) No (b) Yes
37. 37.🧩 Which component senses how bright it is? (a) thermistor (b) resistor (c) buzzer (d) LDR
38. 38.True or false: “compare with a limit” is the process. (a) False (b) True
39. 39.🔺 A current of 3 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
40. 40.True or false: to make a parking alarm, use a distance sensor. (a) False (b) True

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