20 μ C charge is placed inside a closed surface; then flux linked with the surface is φ . If 80 μ C more charge is put inside the surface then change in flux is :-

Question

20 μ C charge is placed inside a closed surface; then flux linked with the surface is φ . If 80 μ C more charge is put inside the surface then change in flux is :- (A) 4 φ (B) 5 φ (C) φ (D) 8 φ

Tardigrade Admin · Accepted Answer

φ propto q ...(i) After addition flux becomes φ'. φ' propto q ' ...(ii) (φ'/φ)=( q 1/ q )=(100/20)=5 φ'=5 φ change influx Δ φ=φ'-φ=4 φ

Q. $20 μ C$ charge is placed inside a closed surface; then flux linked with the surface is $ϕ .$ If $80 μ C$ more charge is put inside the surface then change in flux is :-

$4 ϕ$

$5 ϕ$

$ϕ$

$8 ϕ$

$ϕ \propto q$ ...(i)
After addition flux becomes $ϕ^{'}$ .
$ϕ^{'} \propto q^{'}$ ...(ii)
$\frac{ϕ ^{'}}{ϕ} = \frac{q ^{1}}{q} = \frac{100}{20} = 5$
$ϕ^{'} = 5 ϕ$
change influx $Δ ϕ = ϕ^{'} - ϕ = 4 ϕ$

Q. 20μC charge is placed inside a closed surface; then flux linked with the surface is ϕ. If 80μC more charge is put inside the surface then change in flux is :-

4ϕ

5ϕ

ϕ

8ϕ

ϕ∝q ...(i) After addition flux becomes ϕ′. ϕ′∝q′ ...(ii) ϕϕ′​=qq1​=20100​=5 ϕ′=5ϕ change influx Δϕ=ϕ′−ϕ=4ϕ

Q. $20 μ C$ charge is placed inside a closed surface; then flux linked with the surface is $ϕ .$ If $80 μ C$ more charge is put inside the surface then change in flux is :-

$4 ϕ$

$5 ϕ$

$ϕ$

$8 ϕ$

$ϕ \propto q$ ...(i)
After addition flux becomes $ϕ^{'}$ .
$ϕ^{'} \propto q^{'}$ ...(ii)
$\frac{ϕ ^{'}}{ϕ} = \frac{q ^{1}}{q} = \frac{100}{20} = 5$
$ϕ^{'} = 5 ϕ$
change influx $Δ ϕ = ϕ^{'} - ϕ = 4 ϕ$