When a thin rod of length `'l'` is heated from `t_(1)^(0)C` to `t_(2)^(0)C` length increases by `1%` . If plate of length `2l` and breadth `'l'` made of same material is heated form `t_(1)^(0)C` to `t_(2)^(0)C`, percentage increase in area is

Options

A. `1%`
B. `3%`
C. `4%`
D. `2%`

Explanation

`L_(f) = L (1+ alpha Delta t) rArr (L_(f))/(L) xx 100 = (1+ alpha Deltat) xx 100 = 1%`
`A_(f) = 2L xx L (1+2 alpha Deltat) rArr (A_(f))/(2L xx L) xx 100 = (1 +2 alpha Deltat) xx 100 = 2%`