JEE Mains · Physics · STD 12 - Electromagnetic waves
- JEE Mains 2019
- Medium
- MCQ
A plane electromagnetic wave having a frequency \(n = 23.9\, GHz\) propagates along the positive \(z-\) direction in free space. The peak value of the electric field is \(60\, V/m\). Which among the following is the acceptable magnetic field component in the electromagnetic wave?
Pick an option to check your answer.
Answer & Solution
Correct Answer
(C) \(\vec B = 2 \times {10^{ - 7}}\,\sin \,\left( {0.5 \times {{10}^3}z - 1.5 \times {{10}^{11}}t} \right)\hat i\)
Step-by-step Solution
Detailed explanation
Magnetic field when electromagnetic wave propagates in \(+z\) direction.
\(\mathrm{B}=\mathrm{B}_{0} \sin (\mathrm{kz}-\omega \mathrm{t})\)
where
\(\mathrm{B}_{0}-\frac{60}{3 \times 10^{8}}=2 \times 10^{-7}\)
\(\mathrm{k}=\frac{2 \pi}{\lambda}=0.5 \times 10^{3}\)
\(\omega=2 \pi \mathrm{f}=1.5 \times 10^{11}\)
More questions from Physics
- The critical angle of a medium for a specific wavelength, if the medium has relative permittivity \(3\) and relative permeability \(\frac{4}{3}\) for this wavelength, will be.....\(^o\)JEE Mains 2020 Medium
- Two identical springs of spring constant \('2k'\) are attached to a block of mass \(m\) and to fixed support (see figure). When the mass is displaced from equilibrium position on either side, it executes simple harmonic motion. The time period of oscillations of this sytem is ...... .
JEE Mains 2021 Medium - In the Young's double slit experiment, the distance between the slits varies in time as \({d}({t})={d}_{0}+{a}_{0}\, sin\omega \,t\) ; where \({d}_{0}, \omega\) and \(a_{0}\) are constants. The difference between the largest fringe width and the smallest fringe width obtained over time is given as :JEE Mains 2021 Hard
- A submarine \((A)\) travelling at \(18\, km/hr\) is being chased along the line of its velocity by another submarine \((B)\) travelling at \(27\, km/hr\). \(B\) sends a sonar signal of \(500\, Hz\) to detect \(A\) and receives a reflected sound of frequency \(v\). The value of \(v\) is close to ... \(Hz\) (Speed of sound in water \(= 1500\, ms^{-1}\))JEE Mains 2019 Hard
- In the electric network shown, when no current flows through the \(4\, \Omega \) resistor in the arm \(EB\), the potential difference between the points \(A\) and \(D\) will be ............... \(V\)
JEE Mains 2015 Hard - A ball of mass \(0.5 \mathrm{~kg}\) is attached to a string of length \(50 \mathrm{~cm}\). The ball is rotated on a horizontal circular path about its vertical axis. The maximum tension that the string can bear is \(400 \mathrm{~N}\). The maximum possible value of angular velocity of the ball in rad/s is _______.JEE Mains 2024 Hard
More PYQs from JEE Mains
- A concave-convex lens of refractive index 1.5 and the radii of curvature of its surfaces are 30 cm and 20 cm , respectively. The concave surface is upwards and is filled with a liquid of refractive index 1.3. The focal length of the liquid-glass combination will be _______.JEE Mains 2025 Hard
- A rigid wire consists of a semicircular portion of radius \(R\) and two straight sections. The wire is partially immerged in a perpendicular magnetic field \(B=B_0\ {j}\) as shown in figure. The magnetic force on the wire if it has a current \(i\) is _______.
JEE Mains 2024 Hard - In a Young's double slit experiment \(15\) fringes are observed on a small portion of the screen when light of wavelength \(500 \;\mathrm{nm}\) is used. Ten fringes are observed on the same section of the screen when another light source of wavelength \(\lambda\) is used. Then the value of \(\lambda\) is (in \(\mathrm{nm})\)JEE Mains 2020 Medium
- The increase in the pressure required to decrease the volume \((\Delta V)\) of water is \(6.3 \times 10^7\) N/m\(^2\). The percentage decrease in the volume is _____. (Bulk modulus of water \(= 2.1 \times 10^9\) N/m\(^2\).)JEE Mains 2026 Easy