When a dielectric is inserted into an isolated and charged capacitor, the stored energy decreases to 33% of its original value. What is the value of dielectric constant?

2 1/2 3 1/3

1/3

U = \(\frac{C V^{2}}{2}\) $U' = \frac{C' V^2}{2}$ U' = \(\frac{33}{100}\) \(\frac{C V^{2}}{2}\)  $\frac{C' V^2}{2} =  \frac{33}{100} \frac{C V^{2}}{2}$ C' = k C k C =\(\frac{33}{100}\) C k = 0.33