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There exists an electric field of 100 N/C along the Z-direction. The flux passing through a square of side 10 cm placed in the XY plane inside the electric field is

Asked in RS Academy GUJCET booklet · Electric flux through a surface

• (1) 1.0 N m² C⁻¹
• (2) 2.0 V/m
• (3) 10 V/m
• (4) 4.0 N m² C⁻¹

Step-by-step solution

Why the other options are wrong

• (2) Wrong unit, since V/m measures a field while flux is measured in N m² C⁻¹ (that is, V m); and no single slip gives 2.0 - the flux is EA=100×0.01=1.0.
• (3) Multiplies the field by the side, 100×0.1=10, instead of by the area 0.01 m²; the unit V/m is also that of a field, not a flux.
• (4) No single slip gives 4.0. Sanity check: the area is (0.1)²=0.01 m², so the flux is 100×0.01=1.0 N m² C⁻¹.

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