The periodic time of one oscillation for a simple pendulum is
A
$$2\pi \sqrt {\frac{{\text{g}}}{l}} $$
B
$$\frac{1}{{2\pi }}\sqrt {\frac{{\text{g}}}{l}} $$
C
$$2\pi \sqrt {\frac{l}{{\text{g}}}} $$
D
$$\frac{1}{{2\pi }}\sqrt {\frac{l}{{\text{g}}}} $$
Correct Answer: $$2\pi \sqrt {\frac{l}{{\text{g}}}} $$