Which one of the following statements are incorrect?a)The magnitude of the electric field is attenuated as the wave propagatesb)The energy of the e.m. wave flows along the x-directionc)The magnitude of the electric field of the wave is a constantd)The speed of the wave is the same as c (speed of light in free space )Correct answer is option 'B,C,D'. Can you explain this answer?

Question

Answer

Incorrect statements:

b) The energy of the e.m. wave flows along the x-direction
c) The magnitude of the electric field of the wave is a constant
d) The speed of the wave is the same as c (speed of light in free space)

Explanation:

b) The energy of the electromagnetic (e.m.) wave does not flow along any specific direction. Instead, it is carried by the electric and magnetic fields of the wave. The energy is transferred perpendicular to the direction of wave propagation, forming an oscillating pattern of energy transfer. Therefore, statement b is incorrect.

c) The magnitude of the electric field of an e.m. wave is not constant. It varies sinusoidally as the wave propagates through space. The electric field oscillates between positive and negative values, following a wave pattern. Therefore, statement c is incorrect.

d) The speed of an e.m. wave is not always the same as the speed of light in free space (c). The speed of light in free space is a fundamental constant, approximately 299,792,458 meters per second. However, the speed of an e.m. wave can vary depending on the medium through which it is propagating. In different materials, the speed of light can be slower or faster than the speed of light in free space. Therefore, statement d is incorrect.

Correct statement:

a) The magnitude of the electric field is attenuated as the wave propagates. As an electromagnetic wave travels through space, its energy spreads out over a larger area. This leads to a decrease in the intensity of the wave, and consequently, a decrease in the magnitude of the electric field. This attenuation can be described by the inverse square law, which states that the intensity of the wave decreases with the square of the distance from the source. Therefore, statement a is correct.

Answer

All are correct

Similar Physics Doubts

For an electromagnetic wave traveling in free space, the electric field is given by Which of the following statements are true?

Which of the statements are correct?An electromagnetic wave incident upon a perfectly absorbing surface exerts

A train is moving at 30m/s in still air. The frequency of the locomotive whistle is 500Hz & The speed of the sound is 345m/s. Then which of the following statement is correct:

A Positive point charge is moving in clockwise direction in a circle with constant speed. Consider the magnetic field produced by the charge at a pointP(not centre of the circl e) on the axis of the circle. Which of the following is incorrect.

Consider the following statements about a harmonic oscillator: -1. The minimum energy of the oscillator is zero.2. The probability of finding it is maximum at the mean position.Which of the statement given above is/are correct ?

Top Courses for Physics

Suggested Free Tests

Related Content

Schools

Competitive Examinations

Quick Access Links

Technical Exams