Two charges of 5Q and -2Q are situated at the points (3a,0) and (−5a,0) respectively. The electric flux through a sphere of radius '4a' having center at origin is:
(A)ε02Q
(B)ε05Q✓ Correct
(C)ε07Q
(D)ε03Q
Answer: (B)
Solution
A charge 5Q sits at (3a,0), which lies inside the sphere of radius 4a centred at the origin (since 3a<4a). A charge −2Q sits at (−5a,0), outside the sphere (since 5a>4a).
By Gauss's law only the enclosed charge contributes to the flux:
Φ=ε05Q
Key confirmed: B.
JEE Main · 2024 · 29 Jan 2024 · Shift 1 · Single correct option