Q75 / 90 · JEE Main 2022 (27 Jun Shift 2) · Physics
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 .
In the light of the above statements, choose the correct answer from the options given below.
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 .
In the light of the above statements, choose the correct answer from the options given below.
- ABoth statement I and statement II are true
- BBoth statement I and statement II are false
- Correct answerCStatement I is correct but statement II is false
- DStatement I is incorrect but statement II is true
Solution
According to the Maxwell’s EM theory, the EM waves propagation contains electric and magnetic field vibration in mutually perpendicular direction. Thus, the changing of electric field give rise to magnetic field.
Also, time varying magnetic field produces electric field. According to Faradays law, when magnetic flux changes in the region surrounded by conductor, it produces electric field (induced emf) in conductor.
In a material medium the EM wave travels with speed given by
Thus, statement I is correct but statement II is false.
Hence, the correct answer is option: 'C'.