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Electric Charges and Fields — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectric Charges and Fields1 Mark
MCQ
For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
Assertion (A): The electric flux emanating out and entering a closed surface are $8 \times 10^3$ and $2 \times 10^3 \mathrm{Vm}$ respectively. The charge enclosed by the surface is $0.053\mu\text{C}.$
Reason (R): Gauss's theorem in electrostatics may be applied to verify.
  • A
    Both A and R are true, and R is the correct explanation of A.
     
  • B
    Both A and R are true, but R is not the correct explanation of A.
     
  • C
    A is true but R is false.
     
  • D
    A is false and R is also false.
✓

Answer

  1. Both A and R are true, and R is the correct explanation of A.
Explanation:

According to Gauss's theorem in electrostatics,$\phi=\frac{\text{q}}{\in_0}$

$\phi=\frac{\text{q}}{\in_0}=8.85\times10^{-12}[8\times10^3-2\times10^3]$

$=53.10\times10^{-9}\text{C}=0.053\mu\text{C}.$

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