Heat required to convert $5\ kg$ ice at $0\ ^oC$ into water at $100\ ^oC$ is
$900\ cal$
$900\ kcal$
$500\ cal$
$500\ kcal$
Heat is being supplied at a constant rate to the sphere of ice which is melting at the rate of $0.1 \,gm / s$. It melts completely in $100 \,s$. The rate of rise of temperature thereafter will be ............ $^{\circ} C / s$
If an electric heater is rated at $1000\, W$, then the time required to heat one litre of water from $20\,^oC$ to $60\,^oC$ is
The temperature of equal masses of three different liquids $A, B$ and $C$ are $12°C, 19°C$ and $28°C$ respectively. The temperature when $A$ and $B$ are mixed is $16°C$ and when $B$ and $C$ are mixed is $23°C$. The temperature when $A$ and $C$ are mixed is........ $^oC$
A heater supplying constant power $P$ watts is switched $ON$ at time $t=0 \,min$ to raise the temperature of a liquid kept in a calorimeter of negligible heat capacity. A student records the temperature of the liquid $T(t)$ at equal time intervals. A graph is plotted with $T(t)$ on the $Y$-axis versus $t$ on the $X$-axis. Assume that there is no heat loss to the surroundings during heating. Then,
A kettle with $2\, littre$ water at $27\,^oC$ is heated by operating coil heater of power $1\, kW$. The heat is lost to the atmosphere at constant rate $160\, J/sec$, when its lid is open. In how much time will water heated to $77\,^oC$. (specific heat of water $= 4.2\, kJ/kg$) with the lid open ?