Question

A simple pendulum of length `l_(1)` has frequency 1/4 Hz and another simple pendulum of length `l_(2)` has frequency 1/3 Hz. Then time period of pendulum of length `(l_(1)-l_(2))` is
A. 5 s
B. 1 s
C. `sqrt(7) s`
D. `sqrt(12) s`

Answer 1

Correct Answer - A
`(n_(1))/(n_(2))=sqrt(l_(2)/(l_(1)))`
`(16)/(9)=(l_(2))/(l_(1))`
`(16+9)/(9)=(l_(2)+l_(1))/(l_(1))`
`(25)/(9)=(l_(2)+l_(1))/(l_(1))`
`(5)/(3)=(l_(2)+l_(1))/(l_(1))`