Jayant
Last Activity: 9 Years ago
heat required by water = heat emitted by heater
i.e ms/\T = power × time (since, heat = power × time)
=> time = ms/\T / power
=> time = {1000× 4.186 × (40-10)} / 836 (1 litre = 1kg = 1000 g)
=> time = 150 sec.
method used in the previous post is wrong