What is the name given to \( \mu_0 \)?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Permeability of free space
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).”