Water of volume $2\, L$ in a closed container is heated with a coil of $1\,kW$. While water is heated, the container loses energy at a rate of $160\, J/s$ . In how much time will the temperature of water rise from $27\,^oC$ to $77\,^oC$ ? (Specific heat of water is $4.2\, kJ/kg$ and that of the container is negligible)
$8\,min\, 20\, s$
$6\,min\, 2\, s$
$7\, min$
$14\, min$
An aluminium container of mass $100\,\, gm$ contains $200 \,\,gm$ of ice at $-20^o\,\, C$. Heat is added to the system at the rate of $100 \,\,cal/s$. The temperature of the system after $4$ minutes will be ....... $^oC$ (specific heat of ice $= 0.5$ and $L = 80 \,\,cal/gm$, specific heat of $Al= 0.2\,\, cal/gm/^o C$)
When $0.93\,watt-hour$ of energy is supplied to a block of ice weighing $10\,g,$ it is found that
One kilogram of ice at $0°C$ is mixed with one kilogram of water at $80°C.$ The final temperature of the mixture is........ $^oC$
$($Take : specific heat of water$ = 4200\,J\,k{g^{ - 1}}\,{K^{ - 1}}$, latent heat of ice $ = 336\,kJ\,k{g^{ - 1}})$
$1\ gm$ of ice at $0^o C$ is mixed with $1gm$ of water at $100^o C$ the resulting temperature will be .......... $^oC$
Morning breakfast gives $5000 \,cal$ to a $60 \,kg$ person. The efficiency of person is $30 \%$. The height upto which the person can climb up by using energy obtained from breakfast is ......... $m$