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Statement-1: A light celluloid ball placed in a high-speed jet of gas or water emerging from a tube with a narrow nozzle floats freely within the stream. Statement-2: Because the fluid in the jet moves very fast, the pressure inside the stream is higher than atmospheric pressure. Choose the correct option.
- Statement 1 is true, statement 2 true and statement-2 is a correct explanation for statement-1
- Statement 1 is true, statement 2 is true, statement-2 is not a correct explanation for statement 1
- Statement 1 is true; statement 2 is false
- Statement 1 is false; statement 2 is true.
Correct answer: Statement 1 is true; statement 2 is false
Solution
Statement-1 is correct: the ball is held in the jet because if it drifts to the edge, the high-speed (low-pressure) region in the jet versus the higher static pressure outside pushes it back to the centre, providing a restoring effect. Statement-2 is false: by Bernoulli's theorem, high velocity corresponds to LOW pressure, not pressure above atmospheric. So the reason given is wrong.
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