A battery of emf E0=12V is connected across a 4{m} long uniform wire having resistance 4Ωm. The cells of small emfs E1=2V and E2=4V having internal resistance 2Ω and 6Ω respectively, are connected as shown in the figure. If galvanometer shows no deflection at the point N, the distance of point N from the point A is equal to
1.25 m
Equivalent emf of ε1 and ε2 is
ε=ε1r1+ε2r21r1+1r2=2.5volt
Now VAN=ε
∴(128+16)(4l)=2.5
Solving we get, l = 1.25 m