AP EAMCET201822 Apr 2018Evening ShiftPhysicsElectromagnetic WavesActual
An electromagnetic wave of frequency 2 MHz propagates from vacuum to a non-magnetic medium of relative permittivity 9 . Then its' wavelength
Options
- Aincreases by 100 m
- Bincreases by 50 m
- Cdecreases by 50 mm
- Ddecreases by 100 m
Correct answer
D. decreases by 100 m
Step-by-step solution
In vacuum wavelength, ₀= c f₀ = 3 10^8 2 10^6 =1.5 10^2=150 ~m In medium, speed of wave is v= c _r _r c _r (as medium is non-magnetic) v= c 9 = c 3 =1 10^8 ~ms ⁻¹ Frequency remaining same, wavelength in medium is = v f₀ = 10^8 2 10^6 =50 ~m Wavelength decreases by 100 ~m .