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Electric Charges and Fields — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsElectric Charges and Fields1 Mark
Question
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.
  1. Both A and R are true, and R is the correct explanation of A.
  2. Both A and R are true, but R is not the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion (A): The electric flux emanating out and entering a closed surface are 8 × 103 and 2 × 103Vm 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.
✓

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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