JEE Mains · Physics · STD 11 - 10.1, thermonetry,thermal expansion and calorimetry
- JEE Mains 2022
- Hard
- Numerical
A geyser heats water flowing at a rate of \(2.0 kg\) per minute from \(30^{\circ} C\) to \(70^{\circ} C\). If geyser operates on a gas burner, the rate of combustion of fuel will be \(\dots \; g \min ^{-1}\) [Heat of combustion \(=8 \times 10^{3} Jg ^{-1}\) Specific heat of water \(=4.2 Jg ^{-1} \; { }^{\circ} C ^{-1}\) ]
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(42\)
Step-by-step Solution
Detailed explanation
\(m =2000 \; gm / min\)
Heat required by \(water / min = mS \Delta T\)
\(=(2000) \times 4.2 \times 40 \; J / min\)
\(=336000 \; J / min\)
The rate of combustion \(=\left(\frac{ dm }{ dt } L \right)=336000 \; J / min\)
\(\frac{ dm }{ dt }=\frac{336000}{8 \times 10^{3}} \; g / min\)
\(=42 \; gm / min\)
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