finding angular frequency when current is maximum in circuit
You will get the maximum current when the impedance is minimum.  The impedance of this simple series circuit is:

$$Z = j \cdot \omega \cdot L - j \cdot \dfrac{1}{\omega \cdot C} = j \left( \omega \cdot L - \cdot \dfrac{1}{\omega \cdot C} \right)$$ 

Which we see we can make zero when 

$$\omega \cdot L = \dfrac{1}{\omega \cdot C} \Rightarrow \omega = \dfrac{1}{\sqrt{L \cdot C}}$$

Taking \$L = 1 \text{ henry}\$, \$C = 25 \mu F = 25 \times 10^{-6} \text{ Farad}\$

$$\omega = \dfrac{1}{\sqrt{1 \cdot 25 \times 10^{-6}}} = 200 \text{ rad per sec}$$