JEE Mains · Physics · STD 11 - Fluid mechanics
- JEE Mains 2019
- Hard
- MCQ
Water from a pipe is coming at a rate of \(100\, litres\) per minute. If the radius of the pipe is \(5\, cm\), the Reynolds number for the flow is of the order of : (density of water \(= 1000\, kg/m^3\), coefficient of viscosity of water \(= 1\, mPa\, s\))
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(10^4\)
Step-by-step Solution
Detailed explanation
Reynolds number\( = \frac{{\rho vd}}{\eta }\)
Volume flow rate\( = v \times \pi {r^2}\)
\(v = \frac{{100 \times {{10}^{ - 3}}}}{{60}} \times \frac{1}{{\pi \times 25 \times {{10}^{ - 4}}}}\)
\(v = \frac{2}{{3\pi }}m/s\)
Reynolds number \( = \frac{{{{10}^3} \times 2 \times 10 \times {{10}^{ - 2}}}}{{{{10}^{ - 3}} \times 3\pi }} = 2 \times {10^4}\)
\(Order\,{10^4}\)
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