Two rods, one made of aluminium and the other made of steel, having initial lengths $l_1$ and $l_2$ respectively are connected together to form a single rod of length $(l_1 + l_2)$. The coefficients of linear expansion for aluminium and steel of $\alpha_1$ and $\alpha_2$ respectively. If the length of each rod increases by the same amount when their temperature is raised by $t^oC$, then the ratio $l_1/(l_1 + l_2)$ :-
$\frac{\alpha_1}{\alpha_2}$
$\frac{\alpha_2}{\alpha_1}$
$\frac{\alpha_2}{(\alpha_1+\alpha_2)}$
$\frac{\alpha_1}{(\alpha_1+\alpha_2)}$
Water is used to cool radiators of engines in car because
A lead bullet at $27\ ^oC$ just melts when stooped by an obstacle. Assuming that $25\%$ of heat is absorbed by the obstacle, then the velocity of the bullet at the time of striking ....... $m/s$ ( $M.P.$ of lead $= 327\,^oC$ , specific heat of lead $= 0.03\,cal/g\,^oC$ , latent heat of fusion of lead $= 6\,cal/g$ and $J = 4.2\,joule/cal$ )
The coefficient of apparent expansion of a liquid when determined using two different vessels $A$ and $B$ are ${\gamma _1}$ and ${\gamma _2}$ respectively. If the coefficient of linear expansion of vessel $A$ is $\alpha $, the coefficient of linear expansion of vessel $B$ is
Steam at $100\,^oC$ is passed into $22\,g$ of water at $20\,^oC$ The mass of water that will be present when the water acquires a temperature of $90\,^oC$ (Latent heat of steam is $540\,cal/g$) is ......... $\mathrm{g}$
A clock which keeps correct time at $20\,^oC$ has a pendulum rod made of brass. How many seconds will it gain or lose per day when temperature falls to $0\,^oC$ ? $(\alpha = 18\times10^{-6}/^oC)$