How will the time period of a simple pendulum change when its length is doubled?

Explanation

Time period of a simple pendulum,
`T=2pisqrt(l/g)`
So for two different lengths,
`T_(1)/T_(2)=sqrt(l_(1)/l_(2))`
or, `T_(2)=T_(1)sqrt(l_(2)/l_(1))=T_(1)sqrt(2/1)=sqrt2T_(1)" "["given",l_(2)=2l_(1)]`
Hence, the time period becomes `sqrt2` times when the length is doubled.