Question

C₁ and C₂ are two hollow concentric cubes enclosing charges 2Q and 3Q respectively as shown in figure. The ratio of electric flux passing through C₁ and C₂ is :

(1) 2 : 5

(2) 5 : 2

(3) 2 : 3

(4) 3 : 2

Answer 1

(1) 2 : 5

Flux through \(C_1,\phi _1 = \frac {q_{in}}{\varepsilon _0}= \frac {2Q}{\varepsilon _ 0}\)

Flux through \(C_2 ,\phi _2 = \frac {q_{in}}{\varepsilon _ 0}=\frac {2Q + 3Q}{\varepsilon _0} = \frac {5Q}{\varepsilon _0}\)

\(\frac {C_1}{C_2}=\frac {\phi _1}{\phi _2}=\frac {2Q/\varepsilon_0}{5Q/\varepsilon_0}=\frac {2}{5}\)