JEE Mains · Physics · STD 12 - 8. Electromagnetic waves
The oscillating magnetic field in a plane electromagnetic wave is given by \(B _{ y }=5 \times 10^{-6} \sin\) \(1000\,\pi\left(5 x -4 \times 10^{8} t \right) T\). The amplitude of electric field will be.
- A \(15 \times 10^{2} \,Vm ^{-1}\)
- B \(5 \times 10^{-6} \,Vm ^{-1}\)
- C \(16 \times 10^{12} \,Vm ^{-1}\)
- D \(4 \times 10^{2} \,Vm ^{-1}\)
Answer & Solution
Correct Answer
(D) \(4 \times 10^{2} \,Vm ^{-1}\)
Step-by-step Solution
Detailed explanation
\(B _{0}=5 \times 10^{-6}\) \(v =\) Speed of wave \(=\frac{4 \times 10^{8}}{5}=8 \times 10^{7}\left[\therefore v =\frac{ w }{ k }\right]\) \(E _{0}= vB B _{0}=40 \times 10^{1}\) \(=4 \times 10^{2} V / m\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- Two identical symmetric double convex lenses of focal length \(f\) are cut into two equal parts \(L_1, L_2\) by \(A B\) plane and \(L_3, L_4\) by \(X Y\) plane as shown in figure respectively. The ratio of focal lengths of lenses \(L_1\) and \(L_3\) is ________.
JEE Mains 2025 Medium - If force \(\vec{F}=3 \hat{i}+4 \hat{j}-2 \hat{k}\) acts on a particle having position vector \(2 \hat{i}+\hat{j}+2 \hat{k}\) then, the torque about the origin will beJEE Mains 2022 Easy
- When kinetic energy of a body becomes \(36\) times of its original value, the percentage increase in the momentum of the body will be _______.JEE Mains 2024 Hard
- Two resistors of \(100 \Omega\) each are connected in series with a 9 V battery. A voltmeter of \(400 \Omega\) resistance is connected to measure the voltage drop across one of the resistors. The voltmeter reading is _________ V.JEE Mains 2026 Easy
- A \(0.5 \,kg\) block moving at a speed of \(12 \,ms ^{-1}\) compresses a spring through a distance \(30\, cm\) when its speed is halved. The spring constant of the spring will be \(Nm ^{-1}\).JEE Mains 2022 Medium
- Moment of inertia \((M.I.)\) of four bodies, having same mass and radius, are reported as; \(I _{1}= M\). of thin circular ring about its diameter. \(I _{2}=\) \(M.I.\) of circular disc about an axis perpendicular to the disc and going through the centre, \(I _{3}=\) \(M.I.\) of solid cylinder about its axis and \(I _{4}= M . I.\) of solid sphere about its diameter. ThenJEE Mains 2021 Medium
More PYQs from JEE Mains
- From a lot containing 10 defective and 90 non-defective bulbs, 8 bulbs are selected one by one with replacement. Then the probability of getting at least 7 defective bulbs is :JEE Mains 2026 Easy
- If \(\mathrm{y}(\alpha)=\sqrt{2\left(\frac{\tan \alpha+\cot \alpha}{1+\tan ^{2} \alpha}\right)+\frac{1}{\sin ^{2} \alpha}}, \alpha \in\left(\frac{3 \pi}{4}, \pi\right)\) then \(\frac{d y}{d \alpha}\) at \(\alpha=\frac{5 \pi}{6}\) isJEE Mains 2020 Hard
- When two soap bubbles of radii \(a\) and \(b ( b > a )\) coalesce, the radius of curvature of common surface isJEE Mains 2021 Hard
- When \(M_1\) gram of ice at \(-10\,^oC\) (specific heat \(= 0.5\, cal\, g^{-1}\,^oC^{-1}\)) is added to \(M_2\) gram of water at \(50\,^oC\), finally no ice is left and the water is at \(0\,^oC\). The value of latent heat of ice, in \(cal\, g^{-1}\) isJEE Mains 2019 Medium
- Let \(\mathrm{ABC}\) be an equilateral triangle. A new triangle is formed by joining the middle points of all sides of the triangle \(\mathrm{ABC}\) and the same process is repeated infinitely many times. If \(\mathrm{P}\) is the sum of perimeters and \(Q\) is be the sum of areas of all the triangles formed in this process, then :JEE Mains 2024 Hard
- Let the line passing through the points, \(P(2,-1,2)\) and \(Q(5,3,4)\) meet the plane \(x-y+z=4\) at the point \(R\). Then the distance of the point \(R\) from the plane \(x+2 y+3 z+2=0\) measured parallel to the line \(\frac{x-7}{2}=\frac{y+3}{2}=\frac{z-2}{1}\) is equal toJEE Mains 2023 Hard