CBSE 2023 · Region 3 · Set 1 · Q31 · 5 marks
(i)Define electric flux and write its SI unit.(ii)Use Gauss' law to obtain the expression for the electric field due to a uniformly charged infinite plane sheet.(iii)A cube of side L is kept in space, as shown in the figure. An electric field $\displaystyle \overrightarrow{\mathrm{E}}=(\mathrm{Ax}+\mathrm{B}) \hat{\mathrm{i}} \frac{\mathrm{N}}{\mathrm{C}}$ exists in the region. Find the net charge enclosed by the cube.
(i)Define electric potential at a point and write its SI unit.(ii)Two capacitors are connected in series. Derive an expression of the equivalent capacitance of the combination.(iii)Two point charges $\displaystyle +q$ and $\displaystyle -q$ are located at points (3a, $\displaystyle 0$) and ($\displaystyle 0$, 4a) respectively in $\displaystyle x-y$ plane. A third charge $\displaystyle Q$ is kept at the origin. Find the value of Q , in terms of q and a , so that the electrostatic potential energy of the system is zero.
(i)
Define electric flux and write its SI unit.
(ii)
Use Gauss' law to obtain the expression for the electric field due to a uniformly charged infinite plane sheet.
(iii)
A cube of side L is kept in space, as shown in the figure. An electric field $\displaystyle \overrightarrow{\mathrm{E}}=(\mathrm{Ax}+\mathrm{B}) \hat{\mathrm{i}} \frac{\mathrm{N}}{\mathrm{C}}$ exists in the region. Find the net charge enclosed by the cube.
(i)
Define electric potential at a point and write its SI unit.
(ii)
Two capacitors are connected in series. Derive an expression of the equivalent capacitance of the combination.
(iii)
Two point charges $\displaystyle +q$ and $\displaystyle -q$ are located at points (3a, $\displaystyle 0$) and ($\displaystyle 0$, 4a) respectively in $\displaystyle x-y$ plane. A third charge $\displaystyle Q$ is kept at the origin. Find the value of Q , in terms of q and a , so that the electrostatic potential energy of the system is zero.
Marking-scheme solution
(a)
(i) \(\displaystyle \phi=\vec{\mathrm{E}} \cdot \vec{A}\)
Alternatively: Electric flux is the number of electric field lines passing through an area normally.
Electric Charges and FieldsElectric FluxApplylong_answerhard
More from Electric Charges and Fields
- (i) Two point charges +q and -q are held at (a, 0) and ( -a, 0 ) in x-y plane. Obtain an expression for the…2025 · asked 3×
- An electric dipole consists of two point charges q and -q separated by a distance 2a. Derive an expression…2026 · asked 3×
- Two small solid metal balls A and B of radii R and 2 R having charge densities 2 σ and 3 σ respectively are…2025 · asked 3×
- (i) The electric field in a region is given by E=40 x i N / C. Find the amount of work done in taking a unit…2025 · asked 3×
- Four point charges of 1 μ C,-2 μ C, 1 μ C and -2 μ C are placed at the corners A, B, C and D respectively, of…2024 · asked 3×
- (i) Use Gauss' law to obtain an expression for the electric field due to an infinitely long thin straight…2023 · asked 3×
- Which one of the following statements is correct? Electric field due to static charges is2025 · asked 3×
- A point charge situated at a distance ' r ' from a short electric dipole on its axis, experiences a force F.…2023 · asked 3×
CBSE Class 12 Physics past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.