The time period of the pendulum is affected by the acceleration due to gravity. The tension does not have any effect on the time period of the pendulum and also the mass of the bob does not effect the time period of the pendulum.
[tex]T = 2 \pi \sqrt{\frac{l}{g}}[/tex]
Hence, if the gravity increases then the time period of the pendulum will decreases and it will swing faster.
