Question

A student takes $50 \,g$ wax (specific heat $= 0.6 \,kcal/kg^{\circ}C)$ and heats it till it boils. The graph between temperature and time is as follows. Heat supplied to the wax per minute and boiling point are, respectively

• A. $500 \,cal, 50^{\circ}C$
• B. $1000\, cal, 100^{\circ}C$
• C. $1500 \,cal,\, 200^{\circ}C$
• D. $1000 \,cal, \,200^{\circ}C$

Answer 1

Answer: (C)

Since specific heat $= 0.6 \,kcal/g \times ^{\circ}C$
$= 0.6 \,cal/g \times ^{\circ}C$
From graph it is clear that in a minute, the temperature is raised from $0^{\circ}C$ to $50^{\circ}C$.
$\Rightarrow $ Heat required for a minute $= 50 \times 0.6 \times 50 = 1500 \,cal$.
Also from graph, Boiling point of wax is $200^{\circ}C$.