A rod with circular cross-section area 2cm² 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 $4 π \times 10^{- 6} Wb$ . The relative permeability of the rod is
( Given : Permeability of vacuum $μ_{0} = 4 π \times 10^{- 7} N A^{- 2}$ )

see full answer

Take the SCORE scholarship exam from home and compete for scholarships worth ₹1 crore!*

An Intiative by Sri Chaitanya

125

12.5

$\frac{32}{5}$

$\frac{5}{16}$

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

$ϕ = NBA = NμmiA$

$\Rightarrow μ = \frac{ϕ}{NmiA}$

$\Rightarrow μ = \frac{4 π \times 10^{- 6}}{400 \times \frac{400}{0.4} \times 0.4 \times 2 \times 10^{- 4}}$

$\Rightarrow μ = \frac{4 π}{32} \times 10^{- 6}$

$\Rightarrow μ_{r} = \frac{μ}{μ_{0}} = \frac{\frac{4 π}{32} \times 10^{- 6}}{4 π \times 10^{- 7}} = \frac{5}{16}$

Watch 3-min video & get full concept clarity