JEE Main 2021 — Electrostatics Question with Solution
From: JEE Main 2021 (Online) 24th February Morning Shift
Question
A cube of side 'a' has point charges +Q located at each of its vertices except at the origin where the charge is Q. The electric field at the centre of cube is :
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: D
Correct answer
D
Step-by-step explanation
We can replace Q charge at origin by + Q and 2Q. Now, due to + Q charge at every corner of cube, electric field at centre of cube is zero. So, net electric field at centre is only due to 2Q charge at origin. Vector form of electric field strength,
Here, position vector,
Here, position vector,
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