JEE Main 2020 — Electrostatics Question with Solution
From: JEE Main 2020 (Online) 2nd September Evening Slot
Question
A charge Q is distributed over two concentric
conducting thin spherical shells radii r and
R (R > r). If the surface charge densities on the
two shells are equal, the electric potential at
the common centre is :
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: A
Correct answer
AQ
Step-by-step explanation
Let the charges on inner and outer spheres are Q1 and Q2.
Q1 + Q2 = Q ...(1)
Since charge density '' is same for both spheres, so
=
....(2)
From (1) and (2),
Q2 =
Q1 = =
Potential at centre 'O' =
=
=
= Q
Q1 + Q2 = Q ...(1)
Since charge density '' is same for both spheres, so
=
....(2)
From (1) and (2),
Q2 =
Q1 = =
Potential at centre 'O' =
=
=
= Q
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