Electromagnetic Waves

Generally, temperature of human body is corresponding to which IR and microwave radiations are emitted from the human body.

Step 1: Formula for energy density.
The energy density associated with the magnetic field in an electromagnetic wave is given by: where is the magnetic field strength and is the permeability of free space.
Step 2: Explanation.
This formula gives the energy density in the magnetic field component of an electromagnetic wave.
Final Answer:

Step 1: Understand the relationship of parameters.
The wave vector , angular frequency , and the amplitude are related to the wavelength and frequency, but is independent of the wavelength.
Step 2: Explanation.
The electric field amplitude does not depend on the wavelength or frequency of the wave.
Final Answer:

Step 1: Wavelength and potential difference.
The de Broglie wavelength of a particle is related to its momentum and potential difference: For the proton to have the same wavelength as the electron, it must be accelerated under a potential difference that gives it the same momentum.
Step 2: Calculate the required potential.
Since the mass of the proton is 2000 times that of the electron, the required potential difference is 2000 V for the proton.
Final Answer:

is independent of

Step 1: Understanding the situation.
Doubling the amplitude of an electromagnetic wave doesn't affect the speed of propagation, wavelength, or frequency directly. The wave's characteristics, like frequency and speed, remain unchanged unless a different parameter such as energy is altered.

Step 2: Conclusion.
As the amplitude is doubled, but no changes are made to the wave’s other parameters, we conclude that none of the provided options are fully correct. Therefore, the answer is "Alone of the above is correct."

An electromagnetic wave is created by a charge in motion, not at rest, and it propagates through both electric and magnetic fields. The statement about it propagating through only the electric field is incorrect.

In an electromagnetic wave, the electric field, magnetic field, and the direction of wave propagation are mutually perpendicular. Since the wave is propagating north and the electric field is vertical, the magnetic field must point south.

Cosmic rays are coming from outer space, having high energy charged particles, like -particle, proton etc.

Step 1: The relation between the electric field and magnetic field in an electromagnetic wave is given by: where is the speed of light in vacuum, .
Step 2: Given , the electric field strength is:
Final Answer:

From question,



( velocity of light in vacuum )