CAPE Physics Unit 1 · 2008 (Rest of Region) · Paper 1 · Question Q34

A solar furnace has a concave mirror of collecting area 0.80\text{ m}^2 and the average thermal radiation from the sun reaching the earth is about 750\text{ W m}^{-2}. A small object with heat capacity of 1000\text{ J K}^{-1} is heated by the furnace from 10\ ^\circ\text{C} to 40\ ^\circ\text{C}. The time taken for the heating is

1. (A)30\text{ s}
2. (B)50\text{ s}
3. (C)60\text{ s}
4. (D)100\text{ s}