MOSFET or BJT with Arduino

/*
 * ------------------------------------------
 * |                                        |
 * |          I need more POWER!            |
 * |                                        |
 * |           learnelectronics             |
 * |            16 June 2019                |
 * |                                        |
 * |     A look at using transistors        |
 * |     in your Arduino projects to        |
 * |     overcome the Arduino's 40mA        |
 * |     per pin current limit.             |
 * |                                        |
 * |     www.youtube.com/c/learnelectronics |
 * |                                        |
 * |     [email protected]              |
 * |                                        |
 * ------------------------------------------
 */


// Universal variables

int vPow = 0;
int bulb = 3;





void setup() {

  Serial.begin(9600);
   pinMode(bulb, OUTPUT);


}

void loop() {
  int pot = analogRead(A0);
  vPow = map(pot,0,1023,0,255);
    Serial.print("raw=");
    Serial.println(pot);
    Serial.print("vPow=");
    Serial.println(vPow);


  analogWrite(bulb,vPow);


}