The earth's magnetic induction at a certain point is 7 × 10-5 Wbm -2. This is to be annulled by the magnetic induction at the centre of a circular conducting loop of radius 15 cm. The required current in the loop is

Question

The earth's magnetic induction at a certain point is 7 × 10-5 Wbm -2. This is to be annulled by the magnetic induction at the centre of a circular conducting loop of radius 15 cm. The required current in the loop is (A) 0.56 A (B) 5.6 A (C) 0.28 A (D) 2.8 A

Tardigrade Admin · Accepted Answer

From, B=(μ0 i/2 r), 7 × 10-5=(4 π × 10-7 × i/2 × 5 × 10-2) ∴ i=(7 × 10-5/4 π × 10-6)=5.6 A

Q. The earth's magnetic induction at a certain point is $7 \times 1 0^{- 5} Wb m^{- 2}$ . This is to be annulled by the magnetic induction at the centre of a circular conducting loop of radius $15 c m$ . The required current in the loop is

0.56 A

5.6 A

0.28 A

2.8 A

From, $B = \frac{μ _{0} i}{2 r}$ ,
$7 \times 1 0^{- 5} = \frac{4 π \times 1 0 ^{- 7} \times i}{2 \times 5 \times 1 0 ^{- 2}}$
$∴ i = \frac{7 \times 1 0 ^{- 5}}{4 π \times 1 0 ^{- 6}} = 5.6 A$

Q. The earth's magnetic induction at a certain point is 7×10−5Wbm−2. This is to be annulled by the magnetic induction at the centre of a circular conducting loop of radius 15cm. The required current in the loop is