The capacitance of a capacitor between` 4//3` times its original value if a dielectric slab of thickness `t=d//2` is inserted between the plates (d is the separation between the plates). What is the dielectric consant of the slab?

Explanation

To solve the problem, we need to find the dielectric constant \( K \) of a dielectric slab that is inserted between the plates of a capacitor. The capacitance of the capacitor increases to \( \frac{4}{3} \) times its original value when the slab is inserted.

### Step-by-Step Solution:

1. **Identify the Original Capacitance**:
The original capacitance \( C \) of the capacitor is given by the formula:
\[
C = \frac{\varepsilon_0 A}{d}
...