Class 12 NEET Physics Electromagnetic Waves Questions

The velocity of the light in the medium is written as;
v=‌

1

õE

Here we have µ is the permeability and E is permittivity.
CALCULATION:
Given: Relative permeability, µr=1.0
and relative permittivity, Er=1.44
The velocity of light in the medium is written as;
v=‌

1

õE

µ=µrµo‌ and ‌E=ErEo
Now, using equation (1) we have;
v=‌

1

√µrµoErEo

As we know that Eo=8.854×10−12F∕m and
µo=4π×10−7H∕m
Now, by putting the given values we have;
‌v=‌

1

√1.44×4π×10−7×1×8.854×10−12

‌⇒v=‌

1

√1.44×4×3.14×10−7×1×8.854×10−12

‌⇒v=‌

1

√160.21×10−19

⇒v=2.49×108m∕s