Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 940 · 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.🌈 A resistor has the colour bands orange, green, orange. What is its value in kilo-ohms (kΩ)? =
2. 2.🤖 if (light < 300) { lamp ON } else { lamp OFF }
   The light sensor reads 239. What happens? (a) lamp OFF (b) lamp ON
3. 3.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
4. 4.🔍 Which is the odd one out? (a) an alert on the phone (b) a motion sensor signal (c) the fan starts (d) the pump turns on
5. 5.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
6. 6.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) bigger (d) stay the same
7. 7.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave the TV on standby (c) unplug idle chargers (d) leave fridge door open
8. 8.🔐 Is it a good or a risky habit to ignore update messages? (a) risky habit (b) good habit
9. 9.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
10. 10.🔋 Does a solar panel give electricity or use electricity? (a) gives electricity (b) uses electricity
11. 11.True or false: “one bulb out, all go out” is true of a series circuit. (a) True (b) False
12. 12.Which of these is safe? (a) fly a kite near wires (b) poke things in a socket (c) stay away from pylons (d) open a phone charger
13. 13.⚙️ What is an actuator? (a) a program (b) a battery (c) an output that acts (d) a sensor
14. 14.🔍 Which is the odd one out? (a) a buzzer (b) a water pump (c) a push button (d) a motor
15. 15.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) to save copper only (c) each gets full voltage (d) so all go off together
16. 16.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 10 seconds?
17. 17.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) joins two wires (d) stores a value
18. 18.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
19. 19.⚠️ About how many volts do home sockets in India supply? (a) 1.5 V (b) 12 V (c) 9 V (d) 230 V
20. 20.🔺 A 0.6 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
21. 21.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the pins (b) the voltage regulator (c) the power LED (d) the USB port
22. 22.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
23. 23.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) series (b) parallel
24. 24.True or false: to read app permissions is a good habit. (a) False (b) True
25. 25.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) wire (b) diode (c) bulb (d) switch
26. 26.True or false: a water heater mainly makes movement. (a) True (b) False
27. 27.🧮 Resistors of 33 Ω, 68 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
28. 28.💡 2 identical bulbs are joined in series 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.🔍 Which is the odd one out? (a) dry your hands first (b) touch a switch when wet (c) use small battery cells (d) stop if a part gets hot
30. 30.True or false: a laptop runs many apps at once. (a) True (b) False
31. 31.True or false: to fly kites in open fields is safe. (a) False (b) True
32. 32.💡 A red LED uses 2 V and should get 20 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
33. 33.Which of these is a good habit? (a) share camera links (b) tap unknown app links (c) cover unused cameras (d) accept every permission
34. 34.True or false: the ammeter measures voltage. (a) False (b) True
35. 35.True or false: a thermistor glows using little power. (a) False (b) True
36. 36.🌈 A resistor has the colour bands red, yellow, red. What is its value in kilo-ohms (kΩ)? =
37. 37.True or false: resistance is measured in ohms (Ω). (a) False (b) True
38. 38.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 42 %. What happens? (a) pump ON (b) pump OFF
39. 39.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V ÷ R (c) I = V + R (d) I = R ÷ V
40. 40.🔺 A current of 40 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =

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