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A physical quantity has the SI unit J*m^(-2). What is the dimensional formula of this quantity?

1. [M¹ L¹ T⁻²]
2. [M¹ L⁰ T⁻²]
3. [M¹ L² T⁻¹]
4. [M¹ L⁻¹ T⁻²]

Correct answer: [M¹ L⁰ T⁻²]

Solution

J = M¹ L² T⁻². Dividing by m² (L²) gives M¹ L^(2-2) T⁻² = M¹ L⁰ T⁻².

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