What is the value of \( \frac{\mu_0}{4\pi} \)?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( 10^{-7}\,\mathrm{T\,m\,A^{-1}} \)
NCERT (2026-27):
Magnetic Field Due to a Current Element, Biot-Savart Law – “… The proportionality constant in SI units has the exact value,
\( \displaystyle \frac{\mu_0}{4\pi}=10^{-7}\,\mathrm{Tm/A} \)\( \qquad [4.7(c)] \)
We call μ0 the permeability of free space (or vacuum).”