JEE Mains · Physics · STD 12 - Electromagnetic waves
- JEE Mains 2021
- Medium
- MCQ
A plane electromagnetic wave of frequency \(500\, MHz\) is travelling in vacuum along \(y-\)direction. At a particular point in space and time, \(\overrightarrow{ B }=8.0 \times 10^{-8} \hat{ z } \;T\). The value of electric field at this point is (speed of light \(\left.=3 \times 10^{8}\, ms ^{-1}\right)\) \(\hat{ x }, \hat{ y }, \hat{ z }\) are unit vectors along \(x , y\) and \(z\) direction.
Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) \(-24 \hat{ x }\, V / m\)
Step-by-step Solution
Detailed explanation
\(f =5 \times 10^{8} Hz\)
EM wave is travelling towards \(+\hat{j}\)
\(\overrightarrow{ B }=8.0 \times 10^{-8} \hat{ z } T\)
\(\overrightarrow{ E }=\overrightarrow{ B } \times \overrightarrow{ C }=\left(8 \times 10^{-8} \hat{ z }\right) \times\left(3 \times 10^{8} \hat{ y }\right)\)
\(=-24 \hat{ x } V / m\)
More questions from Physics
- A musician using an open flute of length \(50\,cm\) produces second harmonic sound waves. A person runs towards the musician from another end of a hall at a speed of \(10 \,km/h.\) If the wave speed is \(330\,m/s,\) the frequency heard by the running person shall be close to...... \(Hz\)JEE Mains 2019 Easy
- The potential energy \((U)\) of a diatomic molecule is a function dependent on \(r\) (interatomic distance) as \(U =\frac{\alpha}{ r ^{10}}-\frac{\beta}{ r ^{5}}-3\) where, \(\alpha\) and \(\beta\) are positive constants. The equilibrium distance between two atoms will be \(\left(\frac{2 \alpha}{\beta}\right)^{\frac{a}{b}},\) where a \(=\) ..........JEE Mains 2021 Hard
- A real gas within a closed chamber at \(27^{\circ} \mathrm{C}\) undergoes the cyclic process as shown in figure. The gas obeys \(P V^3=\mathrm{RT}\) equation for the path \(A\) to \(B\). The net work done in the complete cycle is _______.(assuming \(R=8 \mathrm{~J} / \mathrm{molK}\) )JEE Mains 2024 Hard
- Using Young's double slit experiment, a monochromatic light of wavelength \(5000\,\mathring A\) produces fringes of fringe width \(0.5 \,mm\). If another monochromatic light of wavelength \(6000\,\mathring A\) is used and the separation between the slits is doubled, then the new fringe width will be ............... \(mm\)JEE Mains 2022 Hard
- A plane electromagnetic wave of frequency \(20\,MHz\) propagates in free space along \(x\)-direction. At a particular space and time, \(\overrightarrow{ E }=6.6 \hat{ j } V / m\). What is \(\overrightarrow{ B }\) at this point?JEE Mains 2023 Medium
- Two cells are connected between points \(A\) and \(B\) as shown. Cell \(1\) has emf of \(12\,V\) and internal resistance of \(3\,\Omega\). Cell \(2\) has emf of \(6\,V\) and internal resistance of \(6\,\Omega\). An external resistor \(R\) of \(4\,\Omega\) is connected across \(A\) and \(B\). The current flowing through \(R\) will be \(.............A\).
JEE Mains 2023 Medium
More PYQs from JEE Mains
- The equation of wave is given by \(Y=10^{-2} \sin 2 \pi\left(160 t-0.5 x+\frac{\pi}{4}\right)\) Where \(x\) and \(Y\) are in \(m\) and \(t\) in \(s\). The speed of the wave is \(.....\,km h ^{-1}\)JEE Mains 2023 Easy
- As per given figures, two springs of spring constants \(K\) and \(2\,K\) are connected to mass \(m\). If the period of oscillation in figure \((a)\) is \(3 s\), then the period of oscillation in figure \((b)\) will be \(\sqrt{ x }\) s. The value of \(x\) is\(.........\)
JEE Mains 2022 Medium - A particle is projected with velocity \(v_{0}\) along \(x-\) axis. A damping force is acting on the particle which is proportional to the square of the distance from the origin i.e., \(ma =-\alpha x ^{2}.\) The distance at which the particle stops:JEE Mains 2021 Hard
- A bullet of mass \(50 \mathrm{~g}\) is fired with a speed \(100 \mathrm{~m} / \mathrm{s}\) on a plywood and emerges with \(40 \mathrm{~m} / \mathrm{s}\). The percentage loss of kinetic energy is _______.JEE Mains 2024 Hard
- The resistance \(\mathrm{R}=\frac{\mathrm{V}}{\mathrm{I}}\) where \(\mathrm{V}=(200 \pm 5) \mathrm{V}\) and \(I=(20 \pm 0.2) A\), the percentage error in the measurement of \(R\) is _______.JEE Mains 2024 Hard
- Given below are two statements : one is labeled as Assertion \(A\) and the other is labeled as Reason \(R\) Assertion \(A:\) Photodiodes are used in forward bias usually for measuring the light intensity. Reason \(R:\) For a \(p-n\) junction diode, at applied voltage \(V\) the current in the forward bias is more than the current in the reverse bias for \(\left|V_z\right| > \pm V \geq\left|V_0\right|\) where \(V_0\) is the threshold voltage and \(V _{ z }\) is the breakdown voltage. In the light of the above statements, choose the correct answer from the options given belowJEE Mains 2023 Medium