Q.

A few electric field lines for a system of two charges Q1 and Q2 fixed at two different points on the x-axis are shown in the figure. These lines suggest that            [2010]

1 |Q1|>|Q2|  
2 |Q1|<|Q2|  
3 At a finite distance to the left of Q1, the electric field is zero.  
4 At a finite distance to the right of Q2, the electric field is zero.  

Ans.

(1, 4)

Clearly from the figure, electric field lines are originating from Q1 and terminating on Q2.

  Q1 is positive and Q2 is negative.

Number of electric field lines originating from Q1 is more than terminating at Q2.

  |Q1|>|Q2|

Since at a finite distance to the right of Q2, the electric field is zero. The electric field created by Q2 at a particular point will cancel out the electric field created by Q1. But at a finite distance to the left of Q1 the electric field is non-zero.