Q.

Saturated solution of KNO3 with agar-agar is used to make 'salt bridge' because:

1 size of K+ is greater than that of NO3-  
2 velocity of NO3- is greater than that of K+  
3 velocities of both K+ and NO3- are nearly the same  
4 both velocities and size of K+ and NO3- ions are same  

Ans.

(3)