COMEDK 2022 | Electromagnetic Waves Question 5 | Physics

Speed of electromagnetic wave in a medium having relative permittivity $$\varepsilon_r$$ and relative permeability $$\mu_r$$ is (speed of light in air, $$c=3\times10^8$$ m/s)

$${1 \over {\sqrt {{\mu _r}{\varepsilon _r}} }}$$

$${c \over {\sqrt {{\mu _r}{\varepsilon _r}} }}$$

$$c\sqrt {{{{\mu _r}} \over {{\varepsilon _r}}}} $$

$${c \over {{\mu _r}{\varepsilon _r}}}$$

COMEDK 2022

MCQ (Single Correct Answer)

-0

A 30 mW laser beam has a cross-sectional area of 15 mm². The magnitude of the maximum electric field in this electromagnetic wave is given by

[Permuittivity of space, $$\varepsilon_0=9\times10^{-12}$$

Speed of light, $$c=3\times10^8$$ m/s]

1.22 kV/m

12 kV/m

10 kV/m

201 kV/m

COMEDK 2021

MCQ (Single Correct Answer)

-0

The correct arrangement in increasing order of wavelength of X-rays, UV rays, microwave is

microwave, X-rays, UV rays

UV rays, X-rays, microwave

X-rays, UV rays, microwave

microwave, UV rays, X-rays

COMEDK 2021

MCQ (Single Correct Answer)

-0

Which of the following waves are used to treatment of muscles ache?

Ultraviolet

Infrared

Microwave

X-rays

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