A centigrade and a Fahrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fahrenheit thermometer registers $140°F$. What is the fall in temperature as registered by the Centigrade thermometer ...... $^o$

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 $J = 4.2\,joule/cal$ )

If there are no heat losses, the heat released by the condensation of $x$ gm of steam at $100^o C$ into water at $100^o C$ can be used to convert $y$ gm of ice at $0^o C$ into water at $100^o C$. Then the ratio $y : x$ is nearly

A beaker contains $200\,g$ of water. The heat capacity of the beaker is equal to that of $20\,g$ of water. The initial temperature of water in the beaker is $20\,^oC$. If $440\,g$ of hot water at $92\,^oC$ is poured in it, the final temperature (neglecting radiation loss) will be nearest to ........ $^oC$

Two large holes are cut in a metal sheet. If this is heated, distances $AB$ and $BC$, (as shown)

Heat required to melt $1\, gm$ of ice is $80\, cal$. A man melts $60\, gm$ of ice by chewing in one minute. His power is ........ $W$