Q12.The relative permittivity of distilled water is 81. The velocity of light in it will be: (Given μr = 1) (1) 4. 33 × 107 m s−1 (2) 2. 33 × 107 m s−1 (3) 3. 33 × 107 m s−1 (4) 5. 33 × 107 m s−1
What This Question Tests
This question directly applies the formula for the speed of an electromagnetic wave in a medium, given its relative permittivity and permeability, testing basic knowledge of EM wave properties.
Concepts Tested
Formulas Used
v = 1 / sqrt(με)
v = c / sqrt(μr εr)
📚 NCERT Sections This Tests
10.3 — (A) The Refractive Index Of Glass Is 1.5. What Is The Speed Of Light In
Physics Class 12 · Chapter 10
10.3 (a) The refractive index of glass is 1.5. What is the speed of light in glass? (Speed of light in vacuum is 3.0 × 108 m s–1) (b) Is the speed of light in glass independent of the colour of light? If not, which of the two colours red and violet travels slower in a glass prism?
10.1 — Monochromatic Light Of Wavelength 589 Nm Is Incident From Air On A
Physics Class 12 · Chapter 10
10.1 Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency and speed of (a) reflected, and (b) refracted light? Refractive index of water is 1.33.
12.6 — (A) 2.18 × 106 M/S; 1.09 × 106 M/S; 7.27 × 105 M/S
Physics Class 12 · Chapter 12
12.6 (a) 2.18 × 106 m/s; 1.09 × 106 m/s; 7.27 × 105 m/s (b) 1.52 × 10–16 s; 1.22 × 10–15 s; 4.11 × 10–15 s.
📋 Question Details
- Chapter
- EM Waves
- Topic
- Speed of EM waves in a medium
- Year
- 2021
- Shift
- 27 Jul Shift 1
- Q Number
- Q12
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 8: Electromagnetic Waves
More from this Chapter
Q62.Infra red radiation is detected by (1) spectrometer (2) pyrometer (3) nanometer (4) photometer
Q63.Which of the following are not electromagnetic waves? (1) cosmic rays (2) gamma rays (3) β-rays (4) X- rays
Q61.Electromagnetic waves are transverse in nature is evident by (1) polarization (2) interference (3) reflection (4) diffraction
Q2. Dimension of 1 , where symbols have their usual meaning, are μ0ε0 (1) [L−1 T] (2) [L−2 T2] (3) [L2 T−2] (4) [LT−1]