Question

Following are the representative wave-length in the Infra-red, Ultra-violet and X-ray regions of the electromagnetic spectrum $1.0\times {10}^{-6}m,$ $1.0\times {10}^{-8}m$ and $1.0\times {10}^{-10}m$. Which of the following statements is false?

• A. The corresponding frequencies of X-ray, UV and IR are in the ratio of ${10}^4:{10}^2:1$
• B. The corresponding velocities of X-ray, UV and IR are in the ratio of $1:{10}^2:{10}^4$
• C. X-rays, UV and IR waves are electromagnetic waves, These are transverse waves.
• D. None of these

Answer 1

The correct option is A The corresponding frequencies of X-ray, UV and IR are in the ratio of ${10}^4:{10}^2:1$

Wavelength $\lambda =\frac{c}{\nu }$ $\nu =\frac{c}{\lambda }$

${\lambda }_x={10}^{-10}m$

${\lambda }_u={10}^{-8}m$

${\lambda }_I={10}^{-6}m$

${\nu }_x:{\nu }_u:{\nu }_I={10}^{10}:{10}^8:{10}^6$

$={10}^4:{10}^2:1$

Corresponding frequencies of$X-ray,UV,IR$ are in ratio ${10}^4:{10}^2:1$