Two waves are represented by  and 
, then the phase difference between them is
                
                  As we learnt in
Travelling Wave Equation -
 
- wherein
  wave length
 Time period of oscillation
 
                                                     
Phase difference  
Option 1)
This option is incorrect.
Option 2)
This option is incorrect.
Option 3)
This option is correct.
Option 4)
This option is incorrect.