NEET Electromagnetic Waves — Set 20

Question 1

What is the general form of the electric field component of a plane electromagnetic wave propagating along the $ z $-direction as per the document?

Accepted Answer

The document provides the form $ E_x = E_0 \sin(kz - \omega t) $, where $ E_x $ is along the $ x $-axis for a wave propagating along the $ z $-direction.

Question 2

Which of Maxwell's equations shows that there are no magnetic monopoles?

Accepted Answer

Gauss's Law for magnetism, $ \oint \mathbf{B} \cdot \mathrm{d} \mathbf{A} = 0 $, implies that the magnetic flux through a closed surface is zero, indicating no magnetic monopoles.

Question 3

Why are microwaves used in aircraft navigation radar systems?

Accepted Answer

The document explains that microwaves are suitable for radar systems due to their short wavelengths, which allow for precise detection and ranging.

NEET Physics: Electromagnetic Waves — Practice Set 20

Q1. What is the general form of the electric field component of a plane electromagnetic wave propagating along the \( z \)-direction as per the document?

Q2. Which of Maxwell's equations shows that there are no magnetic monopoles?

Q3. Why are microwaves used in aircraft navigation radar systems?

Q4. An electromagnetic wave has a magnetic field given by \( B_y = 5 \times 10^{-8} \sin(3 \times 10^3 z - 9 \times 10^{11} t) \, \text{T} \). What is the wavelength of the wave?

Q5. What does the Ampere-Maxwell Law include as the source of a magnetic field?

Q6. What protects the Earth from excessive ultraviolet radiation?

Q7. An electromagnetic wave in vacuum has a magnetic field amplitude of \( B_0 = 3 \times 10^{-8} \, \text{T} \). What is the electric field amplitude? (Given \( c = 3 \times 10^8 \, \text{m/s} \))

Q8. What is the primary source of ultraviolet radiation mentioned in the document?

Q9. The speed of electromagnetic waves in vacuum is given by \( c = \frac{1}{\sqrt{\mu_0 \varepsilon_0}} \). If \( \mu_0 = 4 \pi \times 10^{-7} \, \text{H/m} \) and \( \varepsilon_0 = 8.85 \times 10^{-12} \, \text{F/m} \), what is the approximate value of \( c \)?

Q10. What did Maxwell's equations predict about the nature of light?