Magnetic Effects Of Current Question 17
Question 17 - 31 January - Shift 1
A rod with circular cross-section area $2 cm^{2}$ and length $40 cm$ is wound uniformly with 400 turns of an insulated wire. If a current of $0.4 A$ flows in the wire windings, the total magnetic flux produced inside windings is $4 \pi \times 10^{-6} Wb$. The relative permeability of the rod is
(Given : Permeability of vacuum
$.\mu_0=4 \pi \times 10^{-7} NA^{-2})$
(1) 12.5
(2) $\frac{32}{5}$
(3) 125
(4) $\frac{5}{16}$
Show Answer
Answer: (3)
Solution:
Formula: Magnetic Flux
$\phi=\mu_r \mu_o \frac{N}{\ell}$ I x A
$\mu_r=125$
Option 3.