AP EAMCET Engineering 2018 Apr 22 Shift 2 Paper

In vacuum wavelength is given by,
λ0=

c

f0

=

3×108

2×106

=1.5×102
=150m
The speed of wave in a medium is given by,
v=

c

√εrµr

≈

c

√εr

Here, the medium is non-magnetic medium.
So,
v=

3×108m∕s

√9

=1×108m∕s
Frequency remaining same, so the wavelength in the medium is,
λ=

v

f0

108

2×106

=50m
Decreases in wavelength is,
Decrease =(150m)−(50m)
=100m