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The Dimensional formula for Electric Flux is ________.

Asked in GUJCET 2024 · Dimensional formula of a named quantity

• (1) M¹L¹T⁻³A⁻¹
• (2) M¹L³T⁻³A⁻¹
• (3) M⁻¹L⁻³T³A¹
• (4) M¹L³T⁻³A¹

Step-by-step solution

Why the other options are wrong

• (1) M¹L¹T⁻³A⁻¹ is the dimensional formula of the electric field itself. It comes from stopping at E and forgetting the area, which contributes a further L².
• (3) M⁻¹L⁻³T³A¹ is the exact reciprocal of the answer -- what you get from writing Gauss's law upside down, (ε₀)/q in place of q/(ε₀).
• (4) M¹L³T⁻³A¹ has the current exponent positive. In E=F/q the charge sits in the denominator, so the flux keeps A⁻¹; with A¹ the flux through a surface would depend on the size of the test charge used to probe the field.

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