A closely wound coil of 100 turns and area of crosssection 1 cm 2 has a coefficient of self-induction 1 mH. The magnetic induction in the centre of the core of the coil when a current of 2 A flows in it, will be:

Question

A closely wound coil of 100 turns and area of crosssection 1 cm 2 has a coefficient of self-induction 1 mH. The magnetic induction in the centre of the core of the coil when a current of 2 A flows in it, will be: (A) 0.22 Wb / m 2 (B) 0.022 Wb / m 2 (C) 0.4 Wb / m 2  (D) 0.04 Wb / m 2

Tardigrade Admin · Accepted Answer

B =(μ0 Ni /2r) =(4 π × 10-7 × 100 × 2 × √π/2 × 10-2) =0.002 Wb / m 2

Q. A closely wound coil of $100$ turns and area of crosssection $1 c m^{2}$ has a coefficient of self-induction $1 m H$ . The magnetic induction in the centre of the core of the coil when a current of $2 A$ flows in it, will be:

$0.22 Wb / m^{2}$

$0.022 Wb / m^{2}$

$0.4 Wb / m^{2}$

$0.04 Wb / m^{2}$

$B = \frac{μ _{0} N i}{2 r}$
$= \frac{4 π \times 1 0 ^{- 7} \times 100 \times 2 \times π}{2 \times 1 0 ^{- 2}}$
$= 0.002 Wb / m^{2}$

Q. A closely wound coil of 100 turns and area of crosssection 1cm2 has a coefficient of self-induction 1mH. The magnetic induction in the centre of the core of the coil when a current of 2A flows in it, will be:

0.22Wb/m2

0.022Wb/m2

0.4Wb/m2

0.04Wb/m2