Concept:
Electric flux:
\[
\Phi = \vec{E} \cdot \vec{A} = EA \cos\theta
\]
Step 1: Field direction:
• Field is parallel to cylinder axis
• Curved surface area is perpendicular to radial direction
Step 2: Angle:
\[
\theta = 90^\circ
\]
\[
\cos 90^\circ = 0
\]
Step 3: Flux:
\[
\Phi = EA \cos 90^\circ = 0
\]
Final Answer:
Zero