Thermal Properties of Matter - Result Question 27

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28. An electric kettle takes $4 A$ current at $220 V$. How much time will it take to boil $1 kg$ of water from temperature $20^{\circ} C$ ? The temperature of boiling water is $100^{\circ} C$.

======= ####28. An electric kettle takes $4 A$ current at $220 V$. How much time will it take to boil $1 kg$ of water from temperature $20^{\circ} C$ ? The temperature of boiling water is $100^{\circ} C$.

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/thermal-properties-of-matter/thermal-properties-of-matter—result-question-27.md (a) $6.3 min$

(b) $8.4 min$

(c) $12.6 min$

(d) $4.2 min$

[2008]

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Answer:

Correct Answer: 28. (a)

Solution:

  1. (a) Heat required to raise the temperature of $1 kg$ water from $20^{\circ} C$ to $100^{\circ} C$ is given by $Q=ms \Delta \theta=(1 \times 4200 \times 80) J$

Power of kettle $(P)=VI=(220 \times 4) W$

$\therefore$ Time taken $=\frac{Q}{P}=\frac{1 \times 4200 \times 80}{220 \times 4}$

$ =381.81 sec=6.36 min $