A lead bullet at $27\,^oC$ just melts when stopped 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 $J = 4.2\,joule/cal$ )
$410$
$1230$
$307.5$
None of the above
A liquid having coefficient of cubical expansion $\gamma $ is filled in the container having coefficient of linear expansion $\alpha $. If on heating the liquid overflows, then which of the following relations is correct?
Three rods of equal length $l$ are joined to form an equilateral triangle $PQR.$ $O$ is the mid point of $PQ.$ Distance $OR$ remains same for small change in temperature. Coefficient of linear expansion for $PR$ and $RQ$ is same, $i.e., \alpha _2$ but that for $PQ$ is $\alpha _1.$ Then
An iron ball of mass $0.2\,kg$ is heated to $10\,^oC$ and put into a block of ice at $0\,^oC.$ $25\,g$ of ice melts. If the latent heat of fusion of ice is $80\,cal/g,$ then the specific heat of iron in $cal/g\,^oC$ is
$50\, gm$ of copper is heated to increase its temperature by $10\,^oC$. If the same quantity of heat is given to $10\, gm$ of water, the rise in its temperature is ........ $^oC$ (Specific heat of copper $=420\, Joule\, kg^{-1}\,^oC^{-1}$)
If the volume of a block of metal changes by $0.12\%$ when it is heated through $20^o\,C$, the coefficient of linear expansion (in per $^oC^{-1}$) of the metal is :-