Share

# Determine, B0, ω, K, and λ. Find Expressions for E and B. - CBSE (Science) Class 12 - Physics

#### Question

Suppose that the electric field amplitude of an electromagnetic wave is E0 = 120 N/C and that its frequency is ν = 50.0 MHz. (a) Determine, B0ω, k, and λ. (b) Find expressions for and B.

#### Solution

Electric field amplitude, E0 = 120 N/C

Frequency of source, ν = 50.0 MHz = 50 × 106 Hz

Speed of light, c = 3 × 10m/s

(a) Magnitude of magnetic field strength is given as:

B_0=E_0/c

=120/(3xx10^8)

=4xx1)^-7 T=400 nT

Angular frequency of source is given as:

ω = 2πν

= 2π × 50 × 106

Propagation constant is given as:

k=omega/c

=(3.14xx10^8)/(3xx10^8)=1.05 "rad"/m

Wavelength of wave is given as:

lambda=c/v

=(3xx10^8)/(50xx10^6)=6.0 m

(b) Suppose the wave is propagating in the positive x direction. Then, the electric field vector will be in the positive y direction and the magnetic field vector will be in the positive z direction. This is because all three vectors are mutually perpendicular.

Equation of electric field vector is given as:

vecE=E_0sin(kw-omegat)hatj

=120sin[1.05x-3.14xx10^8t]hatj

And, magnetic field vector is given as:

vecB=B_0sin(kx-omegat)hatk

vecB=(4xx10^-7)sin[1.05x-3.14xx10^8t]hatk

Is there an error in this question or solution?

#### APPEARS IN

NCERT Solution for Physics Textbook for Class 12 (2018 to Current)
Chapter 8: Electromagnetic Waves
Q: 8 | Page no. 286

#### Video TutorialsVIEW ALL 

Solution Determine, B0, ω, K, and λ. Find Expressions for E and B. Concept: Electromagnetic Waves.
S