(LDR, LCD, DHT11, MQ135, IR, Relay, Bluetooth)
By Ankit Sir
1. LDR sensor kis quantity ko measure karta hai?
A) Temperature
B) Light intensity
C) Humidity
D) Gas
Ans: B
2. LDR ka resistance light intensity badhne par kya hota hai?
A) Badh jata hai
B) Kam ho jata hai
C) Same rehta hai
D) Infinite ho jata hai
Ans: B
3. LDR sensor Arduino ke kis type ke pin se connect hota hai?
A) Digital pin
B) Analog pin
C) PWM pin
D) Power pin
Ans: B
4. LDR ke saath voltage divider circuit me kaun sa resistor commonly use hota hai?
A) 1kΩ
B) 10kΩ
C) 100Ω
D) 1MΩ
Ans: B
5. LCD display Arduino se 4-bit parallel mode me kitne pins use karta hai?
A) 6 pins (RS, E, D4–D7)
B) 10 pins
C) 2 pins
D) 1 pin
Ans: A
6. Arduino me LCD ke liye kaun si library use hoti hai?
A) DHT.h
B) LiquidCrystal.h
C) Wire.h
D) Servo.h
Ans: B
7. LCD 16×2 display me ek line me kitne characters hote hain?
A) 16
B) 20
C) 12
D) 32
Ans: A
8. DHT11 sensor kya measure karta hai?
A) Light
B) Temperature + Relative Humidity
C) Gas
D) Pressure
Ans: B
9. DHT11 ka data pin Arduino me kis type ke pin se connect hota hai?
A) Analog pin
B) Digital pin
C) PWM pin
D) GND
Ans: B
10. Arduino me DHT11 ke liye kaun si library use hoti hai?
A) Adafruit_Sensor.h
B) DHT.h
C) LiquidCrystal.h
D) MQ135.h
Ans: B
11. MQ135 sensor kis gas ko detect karta hai?
A) CO₂, Ammonia, Benzene, Alcohol
B) Oxygen only
C) Hydrogen
D) Methane only
Ans: A
12. MQ135 sensor ka output type kya hota hai?
A) Digital only
B) Analog voltage (0–5V)
C) I2C
D) SPI
Ans: B
13. IR sensor ka main application kya hai?
A) Obstacle detection
B) Temperature measurement
C) Humidity measurement
D) Light measurement
Ans: A
14. IR sensor ka output Arduino me kis pin par jata hai?
A) Analog pin
B) Digital pin (HIGH / LOW)
C) Serial pin
D) I2C SDA
Ans: B
15. Arduino me LED ON karne ke liye kaun sa function use hota hai?
A) digitalRead(pin, HIGH)
B) digitalWrite(pin, HIGH)
C) analogWrite(pin, 255)
D) pinMode(pin, OUTPUT) only
Ans: B
16. LED blink karne ke liye kaun sa combination use hota hai?
A) delay()
B) digitalWrite() + delay()
C) Serial.print()
D) analogRead()
Ans: B
17. Arduino me button input kaise read karte hain?
A) digitalWrite(pin, INPUT)
B) digitalRead(pin)
C) analogRead(pin)
D) pinMode(pin, OUTPUT)
Ans: B
18. Button ke saath pull-up resistor ka use kyun hota hai?
A) Noise avoid aur floating input rokne ke liye
B) Current badhane ke liye
C) Voltage drop karne ke liye
D) LED bright karne ke liye
Ans: A
19. Relay module Arduino ke kis pin se control hota hai?
A) Analog pin
B) Digital pin (signal pin)
C) Power pin only
D) GND only
Ans: B
20. Relay ka main advantage kya hai?
A) 5V Arduino se 220V AC appliances control karna
B) Sirf DC devices control
C) Low current only
D) Temperature measure karna
Ans: A
21. HC-05 Bluetooth module ka default baud rate kya hota hai?
A) 9600
B) 38400
C) 115200
D) 4800
Ans: B
22. HC-05 ko Arduino se kaise connect karte hain?
A) TX → RX, RX → TX
B) TX → TX, RX → RX
C) VCC → GND
D) SDA → SCL
Ans: A
23. Arduino me serial communication start karne ka function?
A) Serial.begin(9600)
B) Serial.start()
C) serialPrint()
D) pinMode(Serial, 1)
Ans: A
24. Serial Monitor me data print karne ke liye?
A) Serial.print("Hello")
B) print("Hello")
C) console.log()
D) digitalWrite()
Ans: A
25. LDR + LED combination ka common project kaun sa hai?
A) Automatic street light
B) Temperature control
C) Water level indicator
D) Gas leak detector
Ans: A
26. DHT11 + LCD se kaun sa project ban sakta hai?
A) Temperature & Humidity display system
B) Light meter
C) Obstacle avoider
D) Bluetooth remote
Ans: A
27. MQ135 + Buzzer + Relay ka use kis project me hota hai?
A) Gas detector with alarm & exhaust fan
B) Light control system
C) Button counter
D) Serial chat
Ans: A
28. IR sensor + LED + Buzzer ka project?
A) Obstacle detection alarm
B) Weather station
C) Bluetooth speaker
D) LCD clock
Ans: A
29. HC-05 + Arduino + Relay ka home automation project kya hota hai?
A) Bluetooth controlled appliances
B) Wired remote system
C) WiFi router
D) Ethernet switch
Ans: A
30. Multiple sensors (LDR, DHT11, IR) use karte time kaun sa pin allocation sahi hai?
A) Analog → A0, A1; Digital → D2, D3
B) Sab digital pins only
C) Sirf serial pins
D) PWM pins only
Ans: A
Prepared By Ankit Sir | HTML MCQ Practice