The string `AB` vibrates in two loops with a tuning fork when block hasngs in air. Now block is completely immersed in water, the string vibrates in three loops with same tuning fork. The specific gravity of block is :

Options

A. `1.2`
B. `1.8`
C. `2`
D. `5//9`

Answer

B

Explanation

The string `AB` ………..
`(T_(1))/(T_(2)) = ((3)^(2))/((2)^(2)) = (9)/(4), implies 4T_(1) = 9T_(2)`
specific gravity of block
`= (wt.in air)/("loss in wt. in water") = (T_(1))/(T_(1)-T_(2))`
`= (1)/(1-(T_(2))/(T_(1))) = (1)/(1-(4)/(9)) = (9)/(5) = 1.8`