Two charge conceptric spherical shell have radii `10.0cm` and `15.0cm.` The charge on the inner shell is `7.50 xx10 ^(-8)C,` and that on the outer shell is `6.33 xx 10 ^(-8)C.` Find the electric field (a) at `r = 12. 0 cm and (b) at r = 20.0` cm.

Explanation

To solve the problem of finding the electric field at two different points due to two concentric spherical shells with given charges, we will use Gauss's Law.

### Given Data:
- Radius of inner shell, \( R_1 = 10.0 \, \text{cm} = 0.1 \, \text{m} \)
- Radius of outer shell, \( R_2 = 15.0 \, \text{cm} = 0.15 \, \text{m} \)
- Charge on inner shell, \( Q_1 = 7.50 \times 10^{-8} \, \text{C} \)
- Charge on outer shell, \( Q_2 = 6.33 \times 10^{-8} \, \text{C} \)

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