The ratio of the time period of a simple pendulum of length $\ell_0$ with a pendulum of infinite length is (Where, R is the radius of earth)

zero $\sqrt{\frac{\ell_0}{R}}$ $\sqrt{\frac{\ell_0+R}{R}}$ $\sqrt{\frac{R}{\ell_0+R}}$

$\sqrt{\frac{\ell_0}{R}}$

$t_1=2 \pi \sqrt{\frac{\ell_0}{g}}$ and $t_2=2 \pi \sqrt{\frac{R}{g}}$