A closely wound flat circular coil of 25 turns of wire has diaineter of 10 cm which carries current of 4 A, the flux density at the centre of a coil will be

Question

A closely wound flat circular coil of 25 turns of wire has diaineter of 10 cm which carries current of 4 A, the flux density at the centre of a coil will be (A) 2.28 × 10-6 T (B) 1.679 × 10-6 T (C) 1.256 × 10-3 T (D) 1.572 × 10-5 T

Tardigrade Admin · Accepted Answer

Number of turns in the coil, n=25 Diameter of coil, d=10 cm =0 .1 m ∴ Radius, r=(0.1/2)=0.05 m Current i=4 A Hence, flux density of the coil at the centre is given by B=(μ0/4 π) × (2 π n i/r) =10-7 × (2 π × 25 × 4/0.05) =1.256 × 10-3 T (∵ μ0=4 π × 10-7 NA -1 m -1)

Q. A closely wound flat circular coil of $25$ turns of wire has diaineter of $10 c m$ which carries current of $4 A$ , the flux density at the centre of a coil will be

$2.28 \times 1 0^{- 6} T$

$1.679 \times 1 0^{- 6} T$

$1.256 \times 1 0^{- 3} T$

$1.572 \times 1 0^{- 5} T$

Q. A closely wound flat circular coil of 25 turns of wire has diaineter of 10cm which carries current of 4A, the flux density at the centre of a coil will be

2.28×10−6T

1.679×10−6T

1.256×10−3T

1.572×10−5T

Number of turns in the coil, n=25 Diameter of coil, d=10cm =0.1m ∴ Radius, r=20.1​=0.05m Current i=4A Hence, flux density of the coil at the centre is given by B=4πμ0​​×r2πni​ =10−7×0.052π×25×4​ =1.256×10−3T (∵μ0​=4π×10−7NA−1m−1)

Q. A closely wound flat circular coil of $25$ turns of wire has diaineter of $10 c m$ which carries current of $4 A$ , the flux density at the centre of a coil will be

$2.28 \times 1 0^{- 6} T$

$1.679 \times 1 0^{- 6} T$

$1.256 \times 1 0^{- 3} T$

$1.572 \times 1 0^{- 5} T$