If a coil of 40 turns and area 4.0 cm 2 is suddenly removed from a magnetic field, it is observed that a charge of 2.0 × 10-4 C flows into the coil. If the resistance of the coil is 80 Ω, the magnetic flux density in Wb / m 2 is

Question

If a coil of 40 turns and area 4.0 cm 2 is suddenly removed from a magnetic field, it is observed that a charge of 2.0 × 10-4 C flows into the coil. If the resistance of the coil is 80 Ω, the magnetic flux density in Wb / m 2 is (A) 0.5 (B) 1.0 (C) 1.5 (D) 2.0

Tardigrade Admin · Accepted Answer

Δ Q=(Δ φ/R)=(n × B A/R) ⇒ B=(Δ Q ⋅ R/n A)=(2 × 10-4 × 80/40 × 4 × 10-4)=1 Wb / m 2

Q. If a coil of $40$ turns and area $4.0 c m^{2}$ is suddenly removed from a magnetic field, it is observed that a charge of $2.0 \times 1 0^{- 4} C$ flows into the coil. If the resistance of the coil is $80 Ω$ , the magnetic flux density in $Wb / m^{2}$ is

0.5

1.0

1.5

2.0

$Δ Q = \frac{Δ ϕ}{R} = \frac{n \times B A}{R}$
$\Rightarrow B = \frac{Δ Q \cdot R}{n A} = \frac{2 \times 1 0 ^{- 4} \times 80}{40 \times 4 \times 1 0 ^{- 4}} = 1 Wb / m^{2}$

Q. If a coil of 40 turns and area 4.0cm2 is suddenly removed from a magnetic field, it is observed that a charge of 2.0×10−4C flows into the coil. If the resistance of the coil is 80Ω, the magnetic flux density in Wb/m2 is

0.5

1.0

1.5

2.0

ΔQ=RΔϕ​=Rn×BA​ ⇒B=nAΔQ⋅R​=40×4×10−42×10−4×80​=1Wb/m2

Q. If a coil of $40$ turns and area $4.0 c m^{2}$ is suddenly removed from a magnetic field, it is observed that a charge of $2.0 \times 1 0^{- 4} C$ flows into the coil. If the resistance of the coil is $80 Ω$ , the magnetic flux density in $Wb / m^{2}$ is

$Δ Q = \frac{Δ ϕ}{R} = \frac{n \times B A}{R}$
$\Rightarrow B = \frac{Δ Q \cdot R}{n A} = \frac{2 \times 1 0 ^{- 4} \times 80}{40 \times 4 \times 1 0 ^{- 4}} = 1 Wb / m^{2}$