# Class 12 Physics Chapter 8 Case Study Question Electromagnetic Waves PDF Download

In Class 12 Boards there will be Case studies and Passage Based Questions will be asked, So practice these types of questions. Study Rate is always there to help you. Free PDF Download of CBSE Class 12 Physics Chapter 8 Electromagnetic Waves Case Study and Passage Based Questions with Answers were Prepared Based on Latest Exam Pattern. Students can solve NCERT Class 12 Physics Electromagnetic Waves to know their preparation level.

In CBSE Class 12 Physics Paper, Students will have to answer some questions based on Assertion and Reason. There will be a few questions based on case studies and passage-based as well. In that, a paragraph will be given, and then the MCQ questions based on it will be asked.

# Electromagnetic Waves Case Study Questions With answers

Here, we have provided case-based/passage-based questions for Class 12 Physics Chapter 8 Electromagnetic Waves

Case Study/Passage Based Questions

Question 1:

Read the passage given below and answer the following questions from 1 to 4

In an electromagnetic wave both the electric and magnetic fields are perpendicular to the direction of propagation, that is why electromagnetic waves are transverse in nature. Electromagnetic waves carry energy as they travel through space and this energy is shared equally by the electric and magnetic fields. The energy density of electromagnetic waves is the energy in a unit volume of the space through which the wave travels.

The fundamental particle in an electromagnetic wave is
(a) photon (b) electron
(c) phonon (d) proton

Answer: (a) Photon is the fundamental particle in an electromagnetic wave.

For a wave propagating in a medium, identify the property that is independent of the others.
(a) velocity
(b) wavelength
(c) frequency
(d) all these depend on each other

Answer: (c) – Frequency u remains unchanged when a wave propagates from one medium to another. Both wavelength and velocity get changed.

The electric and magnetic fields of an electromagnetic waves are
(a) in opposite phase and perpendicular to each other
(b) in opposite phase and parallel to each other
(c) in phase and perpendicular to each other
(d) in phase and parallel to each other

Answer: (c) – The electric and magnetic fields of an electromagnetic wave are in phase and perpendicular to each other.

Question 2:

An electromagnetic wave transports linear momentum as it travels through space. If an electromagnetic wave transfers a total energy U to a surface in time t, then the total linear momentum delivered to the surface is p = U/c. When an electromagnetic wave falls on a surface, it exerts pressure on the surface. In 1903, the American scientists Nichols and Hull succeeded in measuring radiation pressures of visible light where others had failed, by making a detailed empirical analysis of the ubiquitous gas heating and ballistic effects.

The pressure exerted by an electromagnetic wave of intensity I(W m–2) on a non-reflecting surface is (c is the velocity of light)
(a) Ic (b) Ic2 (c) I/c (d) I/c2

Light with an energy flux of 18 W/cm2 falls on a non-reflecting surface at normal incidence. The pressure exerted on the surface is
(a) 2 N/m2 (b) 2 × 10–4 N/m2
(c) 6 N/m2 (d) 6 × 10–4 N/m2

A point source of electromagnetic radiation has an average power output of 1500 W. The maximum value of the electric field at a distance of 3 m from this source (in V m–1) is

(a) 500 (b) 100
(c) 500/3 (d) 250/3