A photo sensitive material is at $9\,m$ to the left of the origin and the source of light is at $7\,m $ to the right of the origin along $x$ -axis. The photosensitive material and the source of light start from rest and move, respectively, with $8 \widehat i \, m / s$ and $4 \widehat i \, m / s$ . The ratio of intensities at $t = 0$ to $t = 3\,s$ as received by the photosensitive material is :-

  • A

    $16 : 1$

  • B

    $1 : 16$

  • C

    $2 : 7$

  • D

    $7 : 2$

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$A$. The energy of a photon is $E=h v$.

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Choose the correct answer from the options given below:

  • [NEET 2024]

An electron and a photon each have a wavelength of $1.00\; nm$. Find

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  • [AIPMT 1988]