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In an experiment to measure the speed of...

In an experiment to measure the speed of light by Fizeau's apparatus, following data are used :
Distance between the mirrors = 12.0 km,
Number of teeth in the wheel = 180.
Find the minimum angular speed of the wheel for which the image is not seen.

Text Solution

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The correct Answer is:
A, B, D

In the given Fizeau's apparatus
`D=12 km=12xx10^-3m`
n=180
`c=3xx10^8m/sec`
We know c=(2Dnomega)/pi`
`rarr w=(pc)/(2Dm)rad/sec`
`=(pc)/(2Dm)xx180/pdeg/s`
`rarr w=180xx3xx10^8/(24xx10^3)xx180`
`=1.25xx10^4deg/sec`
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