JEE Mains · Physics · STD 12 - 8. Electromagnetic waves
A plane EM wave is propagating along \(\mathrm{x}\) direction. It has a wavelength of \(4 \mathrm{~mm}\). If electric field is in y direction with the maximum magnitude of \(60 \mathrm{Vm}^{-1}\), the equation for magnetic field is _______.
- A \(\mathrm{B}_z=60 \sin \left[\frac{\pi}{2}\left(\mathrm{x}-3 \times 10^8 \mathrm{t}\right)\right] \hat{\mathrm{kT}}\)
- B \(\mathrm{B}_z=2 \times 10^{-7} \sin \left[\frac{\pi}{2} \times 10^3\left(\mathrm{x}-3 \times 10^8 \mathrm{t}\right)\right] \hat{\mathrm{kT}}\)
- C \(\mathrm{B}_{\mathrm{x}}=60 \sin \left[\frac{\pi}{2}\left(\mathrm{x}-3 \times 10^8 \mathrm{t}\right)\right]\) i \(\mathrm{i} \mathrm{T}\)
- D \(\mathrm{B}_z=2 \times 10^{-7} \sin \left[\frac{\pi}{2}\left(\mathrm{x}-3 \times 10^8 \mathrm{t}\right)\right] \hat{\mathrm{k} T}\)
Answer & Solution
Correct Answer
(B) \(\mathrm{B}_z=2 \times 10^{-7} \sin \left[\frac{\pi}{2} \times 10^3\left(\mathrm{x}-3 \times 10^8 \mathrm{t}\right)\right] \hat{\mathrm{kT}}\)
Step-by-step Solution
Detailed explanation
\(\mathrm{E}=\mathrm{BC} \Rightarrow 60=\mathrm{B} \times 3 \times 10^8\) \(\Rightarrow \mathrm{B}=2 \times 10^{-7}\) \(\text { Also } \mathrm{C}=\mathrm{f} \lambda\) \(\Rightarrow 3 \times 10^8=\mathrm{f} \times 4 \times 10^{-3}\)…
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
- The length of a seconds pendulum at a height \(h=2 R\) from earth surface will be _______. (Given: \(R =\) Radius of earth and acceleration due to gravity at the surface of earth \(g =\pi^{2}\,m / s ^{-2}\) )JEE Mains 2024 Medium
- Four capacitor each of capacitance \(16 \mu \mathrm{~F}\) are connected as shown in the figure. The capacitance between points A and B is : ______ (in \(\mu \mathrm{F}\)).
JEE Mains 2025 Easy - Two identical capacitors \(\mathrm{A}\) and \(\mathrm{B}\), charged to the same potential \(5\; \mathrm{V}\) are connected in two different circuits as shown below at time \(\mathrm{t}=0\) If the charge on capacitors \(A\) and \(B\) at time \(\mathrm{t}=\mathrm{CR}\) is \(\mathrm{Q}_{\mathrm{A}}\) and \(\mathrm{Q}_{\mathrm{B}}\) respectively, then (Here \(e\) is the base of natural logarithm)
JEE Mains 2020 Medium - An ac current is represented as
\(\mathrm{i}=5 \sqrt{2}+10 \cos \left(650 \pi \mathrm{t}+\frac{\pi}{6}\right) \mathrm{Amp}\)
The r.m.s value of the current isJEE Mains 2025 Easy - In a car race on straight road, car \(A\) takes a time \(t\) less than car \(B\) at the finish and passes finishing point with a speed \(v\) more than that of car \(B.\) Both the cars start from rest and travel with constant acceleration \(a_1\) and \(a_2\) respectively. Then \(v\) is equal toJEE Mains 2019 Hard
- Light is incident from a medium into air at two possible angles of incidence \((A)\, 20^o\) and \((B)\, 40^o\) . In the medium light travels \(3.0\, cm\) in \(0.2\, ns\). The ray willJEE Mains 2013 Hard
More PYQs from JEE Mains
- Charge is distributed within a sphere of radius \(R\) with a volume charge density \(\rho (r) = \frac{A}{{{r^2}}}{e^{ - 2r/a}}\) where \(A\) and \(a\) are constants. If \(Q\) is the total charge of this charge distribution, the radius \(R\) is.JEE Mains 2019 Hard
- The value of the integral \(\int \limits_{1 / 2}^2 \frac{\tan ^{-1} x}{x} d x\) is equal toJEE Mains 2023 Hard
- The \(H\) amount of thermal energy is developed by a resistor in \(10\,s\) when a current of \(4\,A\) is passed through it. If the current is increased to \(16\,A\), the thermal energy developed by the resistor in \(10\,s\) will be \(........\,H\)JEE Mains 2023 Medium
- A moving coil galvanometer has a coil with \(175\, turns\) and area \(1\, cm^2\) It uses a torsion band of torsion constant \(10^{-6}\, N\, -m/rad\). The coil is placed in a magnetic field \(B\) parallel to its plane. The coil deflects by \(10\) for a current of \(1\, mA\). The value of \(B\) (in Tesla) is approximatelyJEE Mains 2019 Medium
- If \(n\) is the number of irrational terms in the expansion of \(\left(3^{1 / 4}+5^{1 / 8}\right)^{60},\) then \(( n -1)\) is divisible byJEE Mains 2021 Hard
- A rod of length eight units moves such that its ends \(A\) and \(B\) always lie on the lines \(x-y+2=0\) and \(y+2=0\), respectively. If the locus of the point \(P\), that divides the rod \(A B\) internally in the ratio \(2: 1\) is \(9\left(x^2+\alpha y^2+\beta x y+\gamma x+28 y\right)-76=0\), then \(\alpha-\beta-\gamma\) is equal to :JEE Mains 2025 Hard