1. Home
  2. Question
  3. Physics
  4. A plane electromagnetic wave of frequency 50 MHz travels in free space along the positive x-direction. At a particular point in space and time, vecE = 6.3 hatj V/m . The corresponding magnetic field vecB , at that point will be:

Q. A plane electromagnetic wave of frequency 50 MHz travels in free space along the positive x-direction. At a particular point in space and time, $\vec{E} = 6.3 \hat{j} V/m$ . The corresponding magnetic field $\vec{B}$ , at that point will be:

JEE Main JEE Main 2019
Question Incomplete/Wrong Wrong Options Wrong Answer Wrong Solution Spelling Mistake Image Missing Website not working properly Other

Solution:

$\left|B\right| = \frac{\left|E\right|}{C} = \frac{6.3}{3 \times10^{8}} =2.1 \times10^{-8} T $
and $ \hat{E} \times\hat{B} = \hat{C} $
$\hat{j} \times\hat{B} =\hat{i} $
$ \hat{B} = \hat{k} $
$ \vec{B} = \left| B\right|\hat{B} = 2.1 \times10^{8} \hat{k} T $

You must select option to get answer and solution

Questions from JEE Main 2019

1. Two point charges $q_1( \sqrt{10} \mu C)$ and $q_2(-25 \; \mu C)$ are placed on the x-axis at x = l m and x = 4 m respectively. The electric field (in V/m) at a point y = 3 m on y-axis is, $\left[\text{take} \frac{1}{4\pi\varepsilon_{0}} = 9\times10^{9} Nm^{2} C^{-2}\right] $

2. A parallel plate capacitor with square plates is filled with four dielectrics of dielectric constants $K_1, K_2, K_3, K_4$ arranged as shown in the figure. The effective dielectric constant K will be :

3. A rod of length 50cm is pivoted at one end. It is raised such that if makes an angle of 30° from the horizontal as shown and released from rest. Its angular speed when it passes through the horizontal (in rad $s^{-1}$) will be $(g = 10ms^{-2})$

4. One of the two identical conducting wires of length L is bent in the form of a circular loop and the other one into a circular coil of N identical turns. If the same current is passed in both, the ratio of the magnetic field at the central of the loop $(B_L)$ to that at the centre of the coil $(B_C)$ , i.e., $R \frac{B_L}{B_C}$ will be

5. The energy required to take a satellite to a height 'h' above Earth surface (radius of Earth = $6.4 \times 10^3 \; km) $ is $E_1$ and kinetic energy required for the satellite to be in a circular orbit at this height is $E_2$. The value of h for which $E_1 $ and $E_2$ are equal, is:

6. The energy associated with electric field is $(U_E)$ and with magnetic field is $(U_B)$ for an electromagnetic wave in free space. Then :

7. A series AC circuit containing an inductor (20 mH), a capacitor $(120 \; \mu F) $and a resistor $(60 \Omega)$ is driven by an AC source of 24 V/50 Hz. The energy dissipated in the circuit in 60 s is :

8. Expression for time in terms of G (universal gravitational constant), h (Planck constant) and c (speed of light) is proportional to :

9. The magnetic field associated with a light wave is given, at the origin, by $B = B_0 [\sin(3.14 \times 10^7)ct + \sin(6.28 \times 10^7)ct]$. If this light falls on a silver plate having a work function of 4.7 eV, what will be the maximum kinetic energy of the photo electrons ? $(c = 3 \times 10^{8} ms^{-1}, h = 6.6 \times 10^{-34} J-s)$

10. 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 :

Physics Most Viewed Questions

1. The increase in pressure required to decrease the 200 L volume of a liquid by 0.004% (in kPa) is (Bulk modulus of the liquid ==2100 MPa)

Maharashtra CET 2006 Mechanical Properties Of Solids

2. Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities $\omega_1$ and $\omega_2$ . They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is:-

NEET 2017 System Of Particles And Rotational Motion

3. To draw maximum current from a combination of cells, how should the cells be grouped?

AFMC 2006 Current Electricity

4. The period of revolution of planet A around the sun is 8 times that of B. The distance of A from the sun is how many times greater than that of B from the sun?

AIPMT 1997 Gravitation

5. An electron jumps from the 4th orbit to 2nd orbit of hydrogen atom. Given the Rydberg's constant $R=10^5 cm^{-1} $ the frequency in hertz of the emitted radiation will be

AFMC 2010 Atoms

6. The diameter of a flywheel is increased by 1%. Increase in its moment of inertia about the central axis is

JIPMER 2015 System Of Particles And Rotational Motion

7. The temperature of 100 g of water is to be raised from 24°C to 90°C by adding steam to it. The mass of the steam required for this purpose is

JIPMER 2015 Thermal Properties Of Matter

8. The spectrum of an oil flame is an example for ...........

KCET 2010 Dual Nature Of Radiation And Matter

9. A body of mass 4 kg is accelerated upon by a constant force, travels a distance of 5 m in the first second and a distance of 2 m in the third second. The force acting on the body is

KCET 2008 Laws Of Motion

10. Two equal forces are acting at a point with an angle of 60$^{\circ}$ between them. If the resultant force is equal to $40\sqrt{3}$, the magnitude of each force is

KEAM 2008 Laws Of Motion

Latest Updates