I suppose what matters is the resistance value connected between terminals 7 and 6 of the 555 timer IC. Now I have set this value to zero. 7 and 6 are shorted which inturn shorts it to pin 2 of the IC. So will the frequency of the wave be at its maximum or what will be the outcome.

I don't know why you find this so difficult to understand.

The capacitor charges through R2+R3 and discharges through R3. On time is determined by the charging time (to 2/3 VCC) and off time is determined by the discharging time (to 1/3 VCC). If you set R3 to 0, discharge time will be determined by the discharge transistor (which is current limited).

 

The pin numbering is incorrect. The standard for both trim pots and panel mount is that pin 3 is the clockwise end of rotation, as viewed from the front of the shaft. See post #9.

ak

dl324 and ak,

Yes I know there is some error regarding the pin numbering and direction of rotation that caused a confusion. According to standards the clockwise end of rotation is pin 3 and the anticlockwise end of rotation is pin 1 as viewed from the front of the shaft. The middle one is pin 2. Thanks for correcting this and making it clear.