An immersion heater with electrical resistance $7\ \Omega$ is immersed in 0.1 kg of water at $20℃$ for 3 min. If the flow of current is 4 A, what is the final temperature of the water in ideal conditions? $\left( Specific\ heat\ capacity\ of\ water = 4.2 imes 10^{3}\ Jkg ight)^{- 1}K^{- 1}$

Question

An immersion heater with electrical resistance $7\ \Omega$ is immersed in 0.1 kg of water at $20℃$ for 3 min. If the flow of current is 4 A, what is the final temperature of the water in ideal conditions? $\left( Specific\ heat\ capacity\ of\ water = 4.2 	imes 10^{3}\ Jkg ight)^{- 1}K^{- 1}$

Dr. Abubacker · Accepted Answer

(d) $\ \ \ \ \ i^{2}Rt = ms\ \mathrm{\Delta}t$
$\Rightarrow \ \ (4)^{2} 	imes 7 	imes 3 	imes 60$
$= 0.1 	imes 4.2 	imes 10^{3} 	imes \left\lbrack T - (20 + 273) ightbrack$
$	herefore\ T = 341\ K = 68℃$

Q. An immersion heater with electrical resistance $7\ \Omega$ is immersed in 0.1 kg of water at $20℃$ for 3 min. If the flow of current is 4 A, what is the final temperature of the water in ideal conditions? $\left( Specific\ heat\ capacity\ of\ water = 4.2 \times 10^{3}\ Jkg \right)^{- 1}K^{- 1}$

Explanation

Reviewed by Dr. Abubacker

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