Question

Given below are two statements:
Statement I: A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves.
Statement II: In a material medium, the EM wave travels with speed
\(V=\frac{1}{\sqrt{µ0ε0}}\) In the light of the above statements, choose the correct answer from the options given below.

• A. Both statement I and statement II are true
• B. Both statement I and statement II are false
• C. Statement I is correct but statement II is false
• D. Statement I is incorrect but statement II is true

Answer 1

The Correct Option is C

To solve this question, we need to examine each statement individually and analyze them based on our understanding of electromagnetic (EM) waves and their propagation properties.

1. Statement I: "A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves."
   • This statement refers to the fundamental concept of electromagnetic wave propagation. According to Maxwell's equations, a changing electric field generates a magnetic field, and a changing magnetic field induces an electric field. This interplay between electric and magnetic fields enables the creation and propagation of electromagnetic waves. Therefore, Statement I is true.
2. Statement II: "In a material medium, the EM wave travels with speed \(V=\frac{1}{\sqrt{µ0ε0}}\)"
   • This statement provides an expression for the speed of EM waves. However, the formula given, \(V=\frac{1}{\sqrt{µ0ε0}}\), represents the speed of light in a vacuum, not in a material medium. In a material medium, the speed of EM waves is given by \(v = \frac{1}{\sqrt{µε}}\), where \(µ\) is the permeability and \(ε\) is the permittivity of the medium. Hence, Statement II is false.

Based on the analysis above:

• Statement I is correct but Statement II is false.

Therefore, the correct answer is: Statement I is correct but statement II is false.