Question 733: Electrostats & Capacitance

Question

Expression for an electric field is given by $$\overrightarrow{\mathrm{E}}=4000 x^{2} \hat{i} \frac{\mathrm{V}}{\mathrm{m}}$$. The electric flux through the cube of side $$20 \mathrm{~cm}$$ when placed in electric field (as shown in the figure) 
is __________ $$\mathrm{V} \mathrm{~cm}$$.

Accepted Answer

The flux will be only from $D E F G$ surface as on the surface $O A B C$ field is 0 and for rest of the surface, area vector is perpendicular to field.
$$
\begin{aligned}
& 	ext { So } \phi=E A \\
& =4000 	imes(\cdot 2)^{2} 	imes \cdot 2 	imes \cdot 2 \\
& =\frac{32}{5} \mathrm{Vm} \\
& =\frac{32}{5} 	imes 100 \mathrm{~V} \mathrm{~cm} \\
& =640 \mathrm{Vcm}
\end{aligned}
$$

Electrostats & Capacitance

Expression for an electric field is given by $\overrightarrow{\mathrm{E}}=4000 x^{2} \hat{i} \frac{\mathrm{V}}{\mathrm{m}}. The electric flux through the cube of side 20 \mathrm{~cm} when placed in electric field (as shown in the figure) is __________ \mathrm{V} \mathrm{~cm}$.

Choose the correct answer: