Question

What force should be applied to the ends of steel rod of cross sectional area `10 cm^(2)` to prevent it form elongation when heated form 273 K to 303 k ? `(alpha " of steel" 10^(-5).^(@)C ^(-1),Y=2xx 10^(11) NH^(-2))`
A. `2 xx 10^(4)N`
B. `3 xx 10^(4)N`
C. `6 xx 10^(4)N`
D. `12 xx 10^(4)N`

Answer 1

Correct Answer - C
`Deltal = (Fl)/(AY)` ……(1)
Increase in length, `Deltal = l alpha Deltat` …..(2)
from (1) and (2), `(FI)/(AY) = l alpha Delta t rArr YAalphaDeltaT`