Using E=E0−ei(kz−ωt) Given, at t=t1,z=z1,E=0 the next zero that occurs in it's neighborhood is at z2, the frequency of the electromagnetic wave at t2 ei(kz1−ωt1)=ei(kz2−ωt2)kz1−ωt1=kz2−ωt2(t2−t1)ω=k(z−z1) where k=λ2π=2πv(t2−t1)=λ×2πv2π(z2−z1) =x×v1(z2−z1)⇒λ×v=(t2−t1)(z2−z1)=C(t2−t1)=C(z2−z1) Frequency is f∝t1 then (t2−t1)1=(z2−z1)C∴ Frequency, f=(z2−z1)3×108
A plane polarized monochromatic EM wave is travelling a vacuum along z direction such that at t= t_1 it is found that the electric field is zero at a…
JEE Main 2018 — Physics Electromagnetism
2018mcqhard
A plane polarized monochromatic EM wave is travelling a vacuum along z direction such that at t=t1 it is found that the electric field is zero at a spatial point z1. The next zero that occurs in its neighbourhood is at z2. The frequency of the electromagnetic wave is:
Official previous-year question
Held on 15 Apr 2018 · Verified 6 Jul 2026.
Options
- A
∣z2−z1∣3×108
- B
∣z2−z1∣6×108
- C
∣z2−z1∣1.5×108
- D
t1+3×108∣z2−z1∣1
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