NEET Electromagnetic Waves — Set 7

Question 1

In the context of electromagnetic waves, why do oscillating charges act as effective sources?

Accepted Answer

Oscillating charges undergo acceleration, producing time-varying electric fields that induce magnetic fields, which sustain each other to form propagating electromagnetic waves.

Question 2

What property of visible light explains its role in photosynthesis?

Accepted Answer

Visible light has wavelengths that correspond to the energy levels needed to excite chlorophyll molecules in plants, driving the photochemical reactions of photosynthesis.

Question 3

An electromagnetic wave in vacuum has a wavelength of $ 8 \, \text{m} $. What is its frequency? (Given $ c = 3 \times 10^8 \, \text{m/s} $)

Accepted Answer

Using $ v \lambda = c $, we have $ v = \frac{c}{\lambda} = \frac{3 \times 10^8}{8} = 3.75 \times 10^7 \, \text{Hz} $.

NEET Physics: Electromagnetic Waves — Practice Set 7

Q1. In the context of electromagnetic waves, why do oscillating charges act as effective sources?

Q2. What property of visible light explains its role in photosynthesis?

Q3. An electromagnetic wave in vacuum has a wavelength of \( 8 \, \text{m} \). What is its frequency? (Given \( c = 3 \times 10^8 \, \text{m/s} \))

Q4. Radio waves are detected using which of the following?

Q5. What enables electromagnetic waves to propagate without a material medium?

Q6. What conclusion did Maxwell reach when the speed of electromagnetic waves matched the speed of light?

Q7. A parallel plate capacitor has a time-varying charge such that \( \frac{dQ}{dt} = 1.2 \, \text{A} \). What is the displacement current between the plates?

Q8. What is a common method to detect radio waves according to the document?

Q9. What is the typical wavelength range of microwaves according to the document?

Q10. Why are infrared waves often associated with thermal imaging?