Which statement is true about electromagnetic waves?a)Electromagnetic waves are longitudinal in natureb)Electromagnetic waves can travel through vacuumc)Velocity of electromagnetic waves is 3 X 109m/sd)Ratio of electric field and magnetic field in electromagnetic field is 2Erms/ BrmsCorrect answer is option 'C'. Can you explain this answer?

Question

Answer

Properties:• Electromagnetic waves are propagated by oscillating electric and magnetic fields oscillating at right angles to each other. Hence (a) is incorrect.
• Electromagnetic waves travel with a constant velocity of 3 x 108 ms-1 in vacuum. Hence (c) is incorrect.
• Electromagnetic waves need no medium of propagation. The energy from the sun is received by the earth through electromagnetic waves. Hence, correct answer is (b).

Answer

Velocity of EM waves is that of speed of light that is 3*   10^8 not 10^9

Answer

Explanation:

Electromagnetic waves are a form of energy that consists of both electric and magnetic fields oscillating perpendicular to each other and perpendicular to the direction of wave propagation. They are produced by the acceleration of charged particles and can travel through space or a medium. Here is a detailed explanation of each statement:

a) Electromagnetic waves are longitudinal in nature:
This statement is false. Electromagnetic waves are actually transverse in nature, meaning the oscillations of the electric and magnetic fields are perpendicular to the direction of wave propagation. Longitudinal waves, on the other hand, have oscillations that are parallel to the direction of wave propagation.

b) Electromagnetic waves can travel through vacuum:
This statement is true. Unlike mechanical waves that require a medium to propagate (such as sound waves requiring air or water), electromagnetic waves can travel through vacuum, which is empty space. This is because they do not rely on the vibration of particles, but rather on the interaction of electric and magnetic fields.

c) Velocity of electromagnetic waves is 3 X 10^9 m/s:
This statement is true. The velocity of electromagnetic waves in a vacuum is approximately 3 X 10^8 m/s, which is the speed of light. This value is denoted by the symbol 'c' and is a fundamental constant in physics. Electromagnetic waves travel at this constant speed regardless of their frequency or wavelength.

d) Ratio of electric field and magnetic field in electromagnetic field is 2Erms/Brms:
This statement is false. The ratio of the electric field (E) to the magnetic field (B) in an electromagnetic wave is not a fixed value. It depends on the properties of the wave and can vary. The relationship between the electric and magnetic fields is described by Maxwell's equations, which are a set of fundamental equations in electromagnetism.

In conclusion, the only statement that is true about electromagnetic waves is that their velocity in a vacuum is 3 X 10^8 m/s (option c).

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