An electrically heated coil is immersed in a calorimeter containing 360 g of water at `10^@C`. The coil consumes energy at the rate of 90 W. The water equivalent of calorimeter and coil is 40 g. The temperature of water after 10 min is

Answer

42

Explanation

Energy supplied by coil = heat gain by water and calorimetry
`rArr Pt = (m_(1)+w) xx S Delta theta`
`rArr 90 xx (10 xx 60) = (360 +40) xx 4.2 xx (theta - 10)`
`theta = 42.14^(@)C`