The number of electric field lines crossing an area Δ S is n1 when normal of Δ vecS is parallel to vecE, while number of field lines crossing same area is n2 when normal of Δ vecS makes an angle of 30° with vecE. Then

Question

The number of electric field lines crossing an area Δ S is n1 when normal of Δ vecS is parallel to vecE, while number of field lines crossing same area is n2 when normal of Δ vecS makes an angle of 30° with vecE. Then (A) n1 = n2 (B) n1 > n2 (C) n1 < n2 (D) cannot say anything

Tardigrade Admin · Accepted Answer

For first case: φ=E Δ S cos 0°=E Δ S For second case: φ=E Δ S cos 30° Thus, in first case the flux crossing the surface is more than the flux crossing through surface in 2 text nd case, so n1 > n2

Q. The number of electric field lines crossing an area $Δ S$ is $n_{1}$ when normal of $Δ S$ is parallel to $E$ , while number of field lines crossing same area is $n_{2}$ when normal of $Δ S$ makes an angle of $3 0^{\circ}$ with $E$ . Then

$n_{1} = n_{2}$

$n_{1} > n_{2}$

$n_{1} < n_{2}$

cannot say anything

For first case: $ϕ = E Δ S cos 0^{\circ} = E Δ S$
For second case: $ϕ = E Δ S cos 3 0^{\circ}$
Thus, in first case the flux crossing the surface is more than the flux crossing through surface in $2^{nd}$ case, so $n_{1} > n_{2}$

Q. The number of electric field lines crossing an area ΔS is n1​ when normal of ΔS is parallel to E, while number of field lines crossing same area is n2​ when normal of ΔS makes an angle of 30∘ with E. Then

n1​=n2​

n1​>n2​

n1​<n2​