A simple pendulum is suspended from the roof of a trolley that moves freely down a plane of inclination θ. The period of oscillation will be
1
\(2 \pi \sqrt{\frac{1}{g}}\)
2
\(2 \pi \sqrt{\frac{1}{g \cos \theta}}\)
3
\(2 \pi \sqrt{\frac{1}{g \sin \theta}}\)
4
\(2 \pi \sqrt{\frac{1}{g\left(1+\sin ^2 \theta\right)}}\)