Question

A thin conducting spherical shell carries a charge of surface charge density $\sigma$. A small elemental part of the shell is removed from it. Consider two points P and Q located very close to the spherical shell. The point P is in the neighborhood of the elementary cavity formed and Q is just outside the shell as shown. Let, $E_P$ and $E_Q$ be the magnitudes of electric field strength at P and Q respectively. Then the ratio of $\frac{E_P}{E_Q}$ is equal to:

• A. Zero
• B. $1$
• C. $0.5$
• D. $2$

Answer 1

The correct option is C $0.5$

Electric field ntensity at pont P due to conductor is
$E_P=\frac{KQ}{2R^2}.....\left(i\right)$
Electric field intensity at point Q due to conductor is
$E_Q=\frac{KQ}{R^2}...\left(ii\right)$
Equation (i) divided by (ii),
So, $\frac{E_P}{E_Q}=\frac{1}{2}=0.5$