Two concentric conducting spherical shells have radii a and b (a

Question

Two concentric conducting spherical shells have radii a and b (a < b) and carry charges +Q and −Q respectively. The potential at the inner shell (with V(∞) = 0) is

Accepted Answer

D. {'text': 'kQ/a − kQ/b', 'label': 'D'}

1. Outside both shells the system is electrically neutral, so V(∞) = 0 (consistent).
2. V at the inner shell = potential due to +Q on it (kQ/a) plus potential due to −Q on the outer shell at radius a, which is kQ/(b) × (−1) = −kQ/b (potential of a uniform shell at a point inside it = kq/R_shell).
3. V_inner = kQ/a − kQ/b > 0.
_Source: NCERT Class 12 Physics Part I, Ch 2 §2.9 application + §2.5_

Answer

{'text': 'kQ/a + kQ/b', 'label': 'A'}

Answer

{'text': 'kQ/b − kQ/a', 'label': 'B'}

Answer

{'text': '0', 'label': 'C'}